I do hate the genre of harem. That is because anything that belongs in the genre of harem didn't put enough into the worldbuilding, the relationships, and the plot for the harem to arise naturally and be as normal and fun to read as a monogamous relationship. It should not be a notable tag. Instead, there should be so many amazing elements with the romance, the magic, the conflict, etc. that other, better tags should crowd out the harem tag so much that you can't put fit it because of the tag limit.
The size doesn't matter. It is the capability of the author to handle it. Typically means, at most, a trio. There are those with more though.
The only harem stories I have enjoyed: Industrial Strength Magic (I hesitate at calling it a harem, because the love goes in all directions, but I think it counts under the definition), AnimeCon Harem (I was a little iffy about it. It has some dark themes), and another I don't want to search for.
Also, enjoy.
https://forum.scribblehub.com/threads/build-a-harem.16004/