Why do some movies just disappear?

I’m a big fan of French-Algerian director Tony Gatlif. His movies usually screen at the European festivals and then disappear, and I don’t understand why.

Here’s a list of prices he’s won:

Cannes Film Festival (2004): Best Director for Exils.
Cannes Film Festival (1993): Un Certain Regard Award for Latcho Drom.
Locarno Film Festival (1997): Silver Leopard and Prize of the Ecumenical Jury for Gadjo Dilo (The Crazy Stranger).
César Awards: Best Original Music for Gadjo Dilo (1997).
CineFest Miskolc International Film Festival (2021): Lifetime Achievement Award.

I remember renting his movies Gadjo Dilo and Latcho Drom back in the video store days, and I’ve found most, but not all, of his other movies online in less than stellar quality—often without subtitles—on sites I maybe wouldn’t recommend using. They don’t stream anywhere, at least not in my area (Sweden, plus international services). The physical release consists of out-of-stock DVDs.

Is it just the fact that he’s not that popular? Are the movies stuck in some kind of copyright hell? What do you think? I can't find any information online. He's even still active; it's not like he made a couple of movies a hundred years ago and disappeared.

I guess I’m just bitter that some of my favorite movies ever aren’t available in good quality anywhere.