I have a 2012 MacBook Pro and use GarageBand and track guitar - all while running Vivaldi. Mind you I'm not doing anything crazy - my projects only ever have a few tracks and I prefer to record via an amp and microphone, but even when I use the amp and pedal sims my "virtual pedal board" has never had more than six pedals on it and I'm not using many plug-ins. If I did start having problems Vivaldi would be the first thing I'd shut down!
I'm into the realms of syncing video via SMPTE, a 500+ track template, clocking external synths and converters. Given how unstable computers used to be in terms of jitter, I daren't even have a file sync app open unless I need to sync a file. I'm sure they're capable of doing it these days with the number of cores available, just what you get conditioned into over time... :- ) Sometimes it's hard to believe technology could have possibly moved on as much as it inevitably has.