With the London-based hedge fund White Square Capital closing after suffering losses on GameStop, does it mean that retail investors actually won?

Yes perhaps? As what chris mentioned, most are in it for the money and are hoping prices for whichever meme stocks to skyrocket. Im sure the term short squeeze has been very hyped in this year but we should be realistic in a logical way. Take AMC, people are saying it will reach $1000 or even $500,000.
As unbelievable as it seems, GME saga has taught us not to go against meme stocks so just swim with the tide n remember to take profits. Paper hands are still better than paper losses. For me, i have been selling puts 10-15% below current prices for an average of 1k ish per week. But i definitely would not want to hold too many AMC stocks since its a matter of time before the trend dies.

Honestly, while the initial hype on Gamestop was driven by 'retail marketing' (on Reddit, Tiktok, Telegram etc.), I can almost guarantee that there are funds playing in this GME/AMC/insert whatever meme stock.

Once the hype was large enough, it would be easy for another fund or financial institution to step in and pump the shares of GME to make a quick buck. I mean, 40 to 400? That's easy money. Plus, funds definitely have ways to get around trading bans or to find liquidity so it's even easier for them to get around the retail investors. End of the day, on a large scale event like this, it always ends up as funds vs funds.

Moreover, with the narrative of retail vs funds, any bagholding or losses suffered by retail can easily be blamed on retail investors as opposed to funds cheating the common man again.

If you're sitting on profits, remember what your exit plan is and don't get greedy. 99% of investors in these stocks aren't fighting for some noble cause, they're just trying to make money. Not that there's anything wrong with that, I did that too kek.