GameStop is in the process of clearancing everything GameCube. Most stores have already sold out. But you might find a GameStop or two in your area that still carries GameCube games. The good news is that this sale is also online and GoozerNation has a list of games you can look for (and if you can't find what you want at GameStop, then Amazon most likely has it).
After a year and a half of work, Mario Party 4 is the first GameCube game to be decompiled, hinting at a fully working PC port in the future.
A mix of first-party and third-party GameCube games should be available on Nintendo Switch 2's app.
NE: "Today, we're looking at how the next Animal Crossing game on Switch 2 could significantly improve its multiplayer with new features."