If you know how to play every single position on the board then you've solved chess. Not even supercomputers can do that with more than six pieces on the board.
It's fun to try different openings, but it's not the fastest way to improve if that's what you're hankering for.
I had the idea to start to play every single opening and defense,all the gambits and all the unsound openings at lease once time,with white and black pieces. Maybe sound a little weird but I see many players who stuck on their repertoire and never try something new in his whole life.
In my case I never start a game with d4, playing all my life e4 as white and chose same responses as black against e4 (mostly c5 Sicilians) and few against d4 like KID,Grunfeld and a few more. So will be interesting start same games with g4,b4,g3,b3 etc and play lines that nobody want to play ,unsound gambits and old and weird stuff because the theory said they are inferior but the majority of us don't understand why. There is chess anyway
I don't Know if is a good idea but I think a complete player must know how to play every single position on the board and know how o get that position and from where they can come.but maybe is not necessary play everything but only understand the positions,but is a good way to know the positions just playing it.
I see same player Who stuck on one opening and system and they do very well ,is a Fide Master here who only play b4 with white and b5 with black and he mastered it .
I want to hear the different opinions and what everybody is doing in special for experienced title player what their think is the best.