Why can't gog make an arcade compilation from midway? Or maybe have an arcade section. Does anyone know of any arcade compilations ;like tetris, midway or snk?

There is an SNK compilation on GOG, actually: https://www.gog.com/en/game/snk_40th_anniversary_collection_copy3

Namco have released arcade compilations on various console generations and on PC.

EDIT: Forum post keeps eating the link for the Midway compilations:
en.wikipedia.org/wiki/Category:Midway_video_game_compilations

On a semi-related note, several of SNK's iconic King of Fighters fighting games are also on GOG.

Well, Gog had some Data East games at one point, but they were delisted. But there's still some Neo Geo games, and the Toaplan games. For Tetris, there's Tetris Forever here but it doesn't have any arcade versions of Tetris like The Grand Master or some of the other more notable versions so it's mostly just interesting from a historical pov than a gameplay pov. Oh and I guess there's also Raiden Legacy although I hear it's not so great a port. And I think Crimson Clover actually got an arcade release eventually, although the version on gog is World Ignition which is behind the current revision (World Explosion) and was delisted on other platforms.

Also several of the companies focused on the preservation of arcade games like Hamster and M2 are focused on consoles.

Now, on steam you do have some more options. There's tons of Capcom collections: Stadium 1 and 2, Fighting Collection 1 and 2, the belt scroller/beat em up collection, the Marvel vs. Capcom collection etc.. There's Namco's Pac Man Museum. City Connection has the Psykio catalog, The Game Tengoku and some Saturn Tribute games (but those are basically ports of a port of the saturn ports of arcade games so I wouldn't really expect much from them lol). There's also Cave games like Mushihimesama, Deathsmiles, Dodonpachi Resurrection, Akai Katana, as well as Treasure's Radiant Silvergun and Ikaruga, the Castle Shikigami series, etc..

Arcade game rights can become insufferably complicated due to distributor and (actual) developer rights.

There is also Atari 50 here with a number of arcade games such as Tempest, missile command to name a few.