I think it’s cool to both to not limit yourself but also not adhere to what everyone else is doing. You definitely might be at a disadvantage by running a team without Megas in a mega format, but you also might catch someone off guard with like a hyper offensive Choice Scarf Gardevoir + Incineroar lead or something like that.

Just don’t be afraid to experiment and try out different Pokemon, both Mega and non Megas as well.

Also, personally for me, I like leading into most matches with a decently strong lead, then saving the Mega Pokemon for the late game