I think restricting moves to 4 like the games made battles worse. That made them predictable, attack patterns repetitive, limited how a battle can play out and how long it could go.
There's a distinct pattern that after the 4 move limit came into play, we saw bigger teams and shorter battles between individual Pokemon.
The Alola League has shown the weakness of such a limitation in such battles when a 1v1 has to be stretched out, like Kiawe v. Acerola and Kiawe v. Sophocles. The same attacking moves were spammed and questionably useful moves like the x4 resisted Signal Beam used just for variety.
And SM as a whole showed that even Z-Moves, an official "5th move", doesn't spice the scripting up because they're essentially a powered-up version of a normal move.
The anime tried to get around this with unconventional applications of those moves, combination moves, or learning a new move during a battle so the bout isn't restricted to just 4 moves, but the results have been pretty hit or miss. I think SM Pikachu has the most flexibility with what he's capable of because Electroweb is creative license do do basically anything the writers want. But Pokemon like Torracat and Lycanroc are a lot more limited.