tab-bar and project.el are fantastic. Projectile of course gives you a load more functionality, but I prefer to use out of the box options when I can. The risk is always pulling in too much and then nuking performance with bloat, or not applying fancy packages consistently (hydra for some things, not for others, for example).
My config is pretty threadbare these days, which is a relief when I plan to rewrite it in literate format.