Live Streaming confusion, ATEM vs OBS or vMix

First, let's clear things up. I have 30+ years as a mercenary IT consultant, but that had nothing to do with video or streaming. I've searched the forums - and of course there are many Youtube videos - but they all seem to be dated by several years. To date we have only done recording, but will be live streaming on Twitch shortly.
I initially had the understanding that all of what I need could be done with the ATEM switches, but I'm seeing so much controversy over using - in addition - OBS,, vMix, Wirecast, etc.
We have:
ATEM Mini Extreme ISO
ATEM Mini Pro
PoE PTZ cameras, iPhone 14 pro max on gimbal to an Apple TV device, and a Mavic Air 2s drone, and all the ancillary equipment needed to run. (e.g. gaming PC, PoE switch, MixEffects/iPad, etc.)

I'm getting great video/audio with our setup and recording with no issues. Why would I need to throw in OBS, vMix or anything else?

So to put it in the simplest way. Streaming from the ATEM/web presenters are great for low motion instances. If you’re doing a panel with just people talking no fast motion stuff like you do with games and you can do it. Most people like myself use things like OBS or vmix because we have more control over quality. Streaming to twitch you are only able to do under 7000kbps. While this may look great if it was just people talking but the moment you add in gameplay 7megs is not enough. OBS and other programs give more options for encoding like Presets which is a key to having clean streams on Twitch.

Many Thanks. I'm guessing I have to dig into protocols, encoding, and bit rates. We do live music such as bands at a local venue or one of the single day festivals we produce. We use a lot of transitions and the only 'fast' movement we capture would be a tight shot on a lead guitar wailing out some pretty extreme rifs. Currently, our common denominator is 1080p at 60fps (or 50-ish) because our 4 PTZ cams are just HD. Everything else has to be stepped down. I'll be upgrading to 4k cameras in a month or so, but since the world seems to only view anything through a phone or tablet, that resolution is fine for now. I'm in an extreme learning phase (water fountain vs. fire hose).

So to put it in the simplest way. Streaming from the ATEM/web presenters are great for low motion instances. If you’re doing a panel with just people talking no fast motion stuff like you do with games and you can do it. Most people like myself use things like OBS or vmix because we have more control over quality. Streaming to twitch you are only able to do under 7000kbps. While this may look great if it was just people talking but the moment you add in gameplay 7megs is not enough. OBS and other programs give more options for encoding like Presets which is a key to having clean streams on Twitch.

Since you are being so helpful, just one question - for the moment - about streaming. So, simply using the ATEM software I was able to start streaming on Twitch - well maybe two questions. If I'm using OBS I presume I should stream from it, correct? What about Twitch Studio, Dashboard, etc. What takes precedence? I noticed last night the 'scene' I was streaming from Twitch Studio was up when I logged into twitch under a personal account. At the same time I went into the ATEM software and started streaming to Twitch and I was seeing the ATEM output. So, who has precedence, OBS, ATEM, Twitch Studio, or the any number of other platforms I see available.? We are definitely going to want to see and respond to comments, get tips or charge for a show. I see other extensions that tout that as their specialty. I am assuming OBS has plugins for that sort of stuff. Side note, I'm playing around with Mix Effects on my iPad and experienced a wee bit of a woody. TMI?

BTW we use multiple front/rear projectors, fog machines, bitchin' lighting, lasers, and more. So, I'm also learning how to program DMX boards, We just got a 40 day show gig and have to step up to the audio using Beringer wireless snakes, and such. Like I said water fountain vs. fire hose. My goal (Santa wish List) is to get LED light panels to cover a 20' w x 10' high area. While I absolutely hate to do it, I'm buying them from China because the costs are sooo much lower. Same with our lasers. With the wattage we have we had to get FCC licensing. Yes, this is me showing off my plumage or measuring my.... and has nothing to do with what I'm asking. Just excited because we got the 40 show contract this morning. I know what some may be thinking, they do this with 1080p PTZ cams? Things have just started falling into our laps. This all started two years ago when we just wanted to put on a single day festival for Gold Star families on memorial day and it has blown up in our faces.

Its like I said before. Twitch Studio does not allow you to FINE tune your streams encoding like OBS lets you. You can see chat from OBS as well as twitch itself. Its up to you. If you are doing just cameras nothing with fast motion then you should be fine with using the ATEM to stream or what ever you like. Just know that when you introduce fast motion you will need a slower encoder.

Its like I said before. Twitch Studio does not allow you to FINE tune your streams encoding like OBS lets you. You can see chat from OBS as well as twitch itself. Its up to you. If you are doing just cameras nothing with fast motion then you should be fine with using the ATEM to stream or what ever you like. Just know that when you introduce fast motion you will need a slower encoder.

I experienced that issue today with Twitch. I did get my free 60 day trial version of vMix about 120 days ago and I never broke it out. but from everything that I can see OBS seems to solve most people's problems so I have downloaded and installed it, and had added it to the PSI of my daily fire hose. thank you