Maybe I'll give it another look.
It's very much a game of team coordination where the power curve is exponential but also can have huge turnarounds since buildings are fragile but drive the economy entirely
So naturally you have to know how to play your specific role or it can throw the game for everyone else
It's not casual like Command and Conquer or something, but nor is it incredibly sweaty like StarCraft or DOTA
I feel like whether a game is considered sweaty or casual is more dependent on the game mode (e.g. ranked vs normal, UMS vs ladder etc).
unfortunately that is a totally fair assessment. its a deep and detailed game with lots of units, commands, mechanics and a few maps that have extremely developed meta.
this is only a problem if you think you can drop into multiplayer on literal day 1 without even doing any of the local/non ai learning options the game provides and expect your team to just deal with you not even knowing the basics.
And even then if you start in "noob" lobbies people are pretty helpful, to the extent that they are trying to play the game and give you tips and can only do/type so much.
so its simple... 1. play the scenerios/vs to learn the basics. also watch some yt basics guides 2. join noob lobbies. 3. when people try to help you and they sound mad/terse/short it helps to assume they are just busy with their own match and are doing their best to play and help you learn. if they give you advice try to take it. 4. do your best and ping out when things are going bad in your lane.
the community on there really is very much "nicer" to noobs that many games, especially ones that are co-op team based. but you do need to have realistic expectations. people will get upset if you mess up their games bc you havent at least tried to learn how to play at all.
You are way out on the edge of the bell curve. You only want to play with similar people. That's fine. But own up to it and don't pretend it's friendly to newbies.