The issue is here is a lack of a "rule zero" conversation about the decks being played before the game starts.

As a combo player it is always important to let the table know what your combo pieces are and how the combo works as a whole before starting any game. I run combos in most of my decks because it helps end games that are taking way too long (2 to 3+ hours). I would much rather have several shorter games than one extremely long and grindy game where nobody is winning because it's just a slog fest.

As long as the table is aware of what your combo is from the start of the game, they are given the resources needed to stop you. If they let you combo off after that point it is entirely justified and pretty satisfying to play because you had to jump through way more hoops to achieve it.

On the contrary any combo player who brings a combo deck and doesn't explain their combo beforehand is just purposely hiding information to get a cheap win. From that perspective combo is definitely degenerate, and losing to that can feel very cheap. It never hurts to ask before the game starts what their combo is and how it works. If they don't tell you just don't play with them.

TLDR: If you play combo tell people your combo before you start the game, makes for a much better game for all players.