Hah, a bit late with this one, mostly because I was trying to solve it. Found by John Overholt over on Mastodon, It’s a big page full of 2,025 different items that you’re to sort, into 45 categories of 45 items each. Because the year 2025 just ended, of course.
Click on an item, then click on another item of the same type. The two will merge together into one item. When you get an item with all 45 of its type it’ll be replaced with a box with the name of its category.

Remembering the locations of the growing categories quickly becomes a major part of the puzzle! When you combine an item with another one, the combined group ends up at the location of the second one you clicked. Use this information to get the categories as close to the upper-left as possible. This will prevent them from moving around too often, and aid your creaking grey matter in recording their places.
Unless I miss my guess, you’ll progress smoothly for a while; you’ll complete one or two specific categories long before any of the others; then at about six to ten categories finished you’ll collide rudely with the taxonomical wall. I had to use Google to get through the last 20% (that’s about 400 items remaining!), and I really think you will too, since everyone has holes in their knowledge.
Below (in ROT13, since it’s a spoiler), I list some of the harder categories to pick up on:
Gbz Unaxf zbivrf, Tbbtyr cebqhpgf, Gbyxvra punenpgref, “jrngure jbeqf,” pbyyrpgvir abhaf, HF ICf, xvaqf bs cnfgn (whfg ubj znal xvaqf NER gurer?!), “jrngure jbeqf,” Zneiry Pvarzngvp Havirefr punenpgref, pbzchgre ynathntrf, ynetr pbzcnavrf, ybtvpny snyynpvrf, purrfrf, shpxvat PBPXGNVYF (V qba’g qevax) naq, zbfg vashevngvat bs nyy vs lbh’er abg n ynjlre, yrtny qbpgevarf.