Start to cap the number of cards in decks based on which card it is
Back in sometime between 2013-2016 there was a steam game called Magic Duels. Of course, like Arena, it was a random match oriented game.
However, unlike this game, who ever developed it realized it was a good idea for the purpose of fairness and to keep people from getting consistent 4-5 turn win decks or overpowered decks that consistently win, they realized it was a good idea to cap the quanity of certain cards allowed in deck. So you couldn't make a deck with only 8-9 quadruplets of the strongest cards in the game. At best you could only run 1-2 of those cards. Meanwhile to pad out the deck, you had to run the other cards that were not nearly as strong.
Of course, in the current standard format, there is an excess of overpowered cards and providing such reasonable limitations on numbers of cards should also be paired with a lot of bans or the restriction of which cards could be put into the same deck in order to prevent decks from being played that make the game into a four-to-five turn waste of time and no fun at all for the other player.
It's one thing to run all these overpowered decks where people sheepishly just copy a deck someone uploaded and essential keep themselves from playing half the game (making THEIR OWN deck) in a tournament setting. It's another thing to let a RANDOM match where you do not get to sideboard cards into the game and you never have a clue about what you're going to play against next to be anything goes.
There needs to be a lot more restrictions on how decks can be built and even what cards can be used in random matches.