For evidence:

In these past videos, Kevin’s roles haven’t been appearing at all and Luke’s been appearing less and less, taking only minor speaking roles and mainly only playing the bit of having no video ideas left. They’ve mainly been keeping all appearances to the characters with other or no voice actors.

Glitch has been expanding, currently announcing active or future work on at least 4 different shows.

In WOTFI 2025, SMG4 spent a large part of it reminiscing on how much he had achieved.

WOTFI 2025 ended with a final rematch showcasing all the SMG4 characters defeating all the enemies, carefully tying up all the loose ends by eliminating Mr. Puzzles, WPNZ, and the stupid blob.

If this isn’t evidence enough pointing towards his sad announcement being the end of SMG4 as seen at the end of WOTFI 2025 then I don’t know what is.

If this is true and you’re reading this Luke and/or Kevin, the please know this:
While I and many others may not have exactly loved what you have put out lately, I still do greatly appreciate all that you have done for me over the years. I believe that you are the only YouTuber that I actually vividly remember when I first found you. It was 7 years ago. I was in fifth grade when my friend first introduced me to you in your If Mario was in Baldi’s Basics video. From that point onwards, through thick and thin, I’ve watched all your videos. I wish I could say more to compliment just how great what you’ve made is but all I have is this: you are a bastion of creativity in a corporate desert of soullessness. Keep on shining bright!

Also if you are leaving can you please allow us fans to continue what you’ve started by releasing all models, maps, dupes, saves, and whatever else you use in GMod, SFM, and Blender?