should i upgrade my 2012 mbp 15"

so hello guys, i got this top end mid-2012 mbp 15" and last supported macos on this machine is catalina, this mac as i know is pretty much similar to early 2013 mbp 15" i dont need any debates about how bad this machine is or how good, at this point it is my main machine that i work on and watch youtube and stuff on, (honestly i dont work on it at all lol, all i do is watch youtube and play some games, i can say that by "work" i mean doing school related kinda stuff in microsoft programs, and also some video editing in capcut)

so still, i noticed that safari pretty much sucks on it cuz its already obsolete, im forced to use microsoft edge cuz i was using it before on other device and it has best "vibes" and style and features that other browsers havn't, (im not gonna use firefox ever, i hate every browser except edge and safari, and still im stuck on edge only because safari is obsolete on this macos!!! also safari doesnt supports any normal working adblocks lol)

in total i want to get usable safari, some new look and features and also some of the apps that are not supported on Catalina, i want get more "live" machine, i mean, its pretty much dead corpse running only because im forcing it to run but, idk i love this machine and im not considering of buying any newer version of macbook or even windows books, ewww windows, i hate windows.

SO BRIFELY SPEAKING: i have done upgrading it to big sure before but i didnt liked it back than cuz idk, but i think the time has come and i really need something newer than catalina, but im worried that my hardly breathing mac gonna die if i even dare to put a something more complex than Catalina on it, so im asking you a questionS... i wonder:

1. does BATTERY LIFE gonna suffer on it? i just installed the new battery and the life changed from 2 hours to 2 and a half... lol thats sucks, anyways, does new macos gonna completely kill battery life on it OR maybe it would stay the same or even get better? i wonder cuz i want to use this corpse outside the house too... so battery life is kinda important to me

2. HOW does the new macos gonna effect on performance? guys its really important cuz when TECH COMPANY MAKES NEW OS THEY USUALY RUIN OLDER MACHINES CUZ COMPLEX LOOK THAT IS ALL JUST EYECANDY DOES NOT WORKS WELL ON HARLDY BREATHING OLD TECH, so i wonder, does the temperature gonna rapidly increase on this mac and burn me alive when ill be watching some dum youtube videos, or the difference is not gonna be that big, also i dont want to turn my mac into slide show stand, does all the new animations works good on this kind of machines?

3. last third question, i was considering to install the Big Sur but i hate that os cuz its idk, ugly? they took IOS style and ruined macos by stretching its look on macos, now all the thousand dollar tech looks like teenager girls iphone 11, but still, i love how they normalized the look in older updates, AND also if we dont rely on appearance, i heared that some guys are installing ventura on this old machines, im wondering why? does the ventura works better or it has other benefits? or maybe cuz they want even more features than big sur can offer, cuz yeah i just bullied macos big sur BUT if its more stable, less battery and performance consumer THAN newer macoses (lol macoses is fuuny word) than its my choice.

in total: 1.does it gonna effect battery life in worst way? 2.does performance will SUCK? 3.which macos should i install?

please answer if you want to help me pls