Safari 17 on Sonoma is basically just the Safari you've used before plus profiles and single site browsers. If you're having specific problems with sites in previous versions of Safari it probably isn't fixed 17 or at least few of the issues I've encountered have been fixed.
Currently I'm on Firefox but go back and forth between it and Safari. What might inform which browser is more suitable is what OS level features you use like Apple Pay, Single-site-browser/Add to Dock, and Safari tab syncing with iOS all of which are only available in Safari.