If I sell you a burger, I haven’t limited your dinner.

Instagram offers what they offer. A forum for a topic or a medium offers something to you. The fact that they’ve chosen not to offer other things isn’t a limitation on your expression, any more than my burger shop is for not selling salads.

And we're allowed to say Instagram is a bad burger shop, we don't like their burgers and we don't want to buy their burgers. We can choose to do business with someone else, and make use social pressure on the people who still use Instagram.

We don't owe Instagram some sort of being nice or saying nice things. If they run a subpar business that punishes freedom of expression, we can call that out and say it sucks.

You're, of course, welcome to not like Instagram, and to not do business with them, and to do business with other people, and to suggest that other people shouldn't use Instagram.

But it's absolute baloney to claim that they punish freedom of expression because the venn diagram of "content they're willing to host on their infrastructure" and "content you want to publish" aren't perfectly aligned. Calling my burger shop bad because it doesn't serve salads is similarly baloney.