Yugioh should copy other card games that have mana system. The bad part about Yugioh evenin TCG/OCG is that if you have a way to draw your entire deck you can use all cards in the same turn. Mana system will make strategy matter more. Also stronger cards require more mana to be used is a very easy balancing system.
With mana system, it's not Yugioh anymore.
Balancing system in Yugioh is different: once per turn, once per duel, activation requirements, etc. That's why errata exist
The problem with Yugioh is abuse of cards/not diverse in play.
To balance it, I suggest Konami to make more strict deck-building rule. Like, mana system that act like cost in deck-building. Cards will divided into category with different amount of mana, and a deck can only contain certain amount of mana.
If I wanted to play a game with a mana system, then I would play another game instead. The reason I play Yugioh is because it doesn't have such a system behind it.
It's too late for yugioh to make a change like that. Imagine if suddenly konami says "hey now you have a limit of how many monsters you can summon general, now you can summon 3 at most"
A game like Yu-Gi-Oh that dedicated all of its ressources into TCG is LOSING in a TCG contest against Pokémon which dedicated only a portion of its ressources into TCG.
I guess the anti-f2p policy of Konami is doing something.
I'm just thankful to Konami setting ecample for future TCG games. Games like legends of runeterra surely saw it form Yugioh that letting a player use infinite number of cards without cost per turn is not healthy for the game while still having some aspect of yugioh in the game.
"That TCG game you mentioned is more f2p friendly than duel links?
Is it a good game to switch to?".
Yeah it is. Main reason is that there is no gatcha in Legends of runeterra, they give you resources to craft the cards instead. Every cards are craftable ang the game just gives you so much resources to craft.