I love Yugioh, still actively play the TCG, but master duel's release and its current state is so ♥♥♥♥.
If you were a new player to Yugioh, the tutorials barely helped you, there are no available ingame resources which guide you, a newbie who knows ♥♥♥♥ to nothing about this game. Yugioh is already an extremely complicated game, and MD did almost nothing to help.
Returning players really just want to play your ♥♥♥♥♥♥ decks and live the nostalgia, there's no mode other than ranked and private matches at the time, so your first game on you play against FULL POWER DRYTRON HERALD, without an ounce of knowledge on how to play this modern game. you move on from that game and you go "wow that was horrible," you then match against STUN LOCK ELDLITCH IN A BEST OF 1 FORMAT. Both decks which are unbelievably toxic to play against, for a new, returning and constant player. The only deck on release which actively made you interact with your opponent was Tri-Brigade and thank god it was one of the best decks at release. EVEN THEN WIND BARRIER STATUE WAS UNLIMITED, SO YOU COULD LOCK YOUR OPPONENT OUT OF SUMMONING.
Even in 2025, 3 years after the release of Master Duel, there are still many problems which flood this game, the banlists are abysmal nothing burgers, yeah you get it every month but there's barely any changes, cards are left too long on them or are just not hit (hint hint apollousa is still ♥♥♥♥♥♥♥ LEGAL SOMEHOW).
With every new set, there are more and more URs (just look at mementos) which you have to craft or pack open.

POSITIVES:
This game is super generous with the gems, you get enough at the start to make a new deck and with every new season/bp, you get enough to open packs and build another deck. So essentially play the game, you get rewarded.
The ui is really good, nothing wrong with the actual simulator itself.
Crafting system is super nice, compared to ygo duel links and other tcg simulators thank god there is one.
Accessories are really cool and cheap (laughs at mtg players) with some being time limited but theyre always easy to get.

The game is still enjoyable, with alternate formats you should much rather play those instead of master duel, however if you enjoy md so be it.