Arin and Danny moving on is something that will inevitably happen. I'd hate to see it happen, and when it does I'd hope they prepare for it, announce it ahead of time, and close up all currently opened series'. I'm sure one day PB & Jeff will also move on. Jirard and Alex will move on. All my favorites will stop doing their thing. But maybe by then others will replace them. I'd hate for Lazy Game Reviews, Nostalgia Nerd (Not Critic), TechMoan and 8-Bit Guy to all stop at once. But I'm sure other old tech reviewers would crop up.
I mean as long as it's announced as a plan I don't mind as much. The Jon departure happened so fast. It really should have been announced but I have a feeling it was just Jon getting a sudden change of heart and deciding "you know what, I don't like this plan. I am leaving because I don't want this to be my life" one day and hopping right on a plane. So I'd hope if Arin or Danny ever decide they can't do it anymore they'll have a bunch of stuff in the pipeline and will have plenty of time to make announcements and wind things down. (Unless they just get a replacement for Danny or Arin and continue. I'd guess Danny would stop before Arin would.)
What we have is much better than the one-a-day-maybe-but-sometimes-not videos we got during the Jon days right before the "reboot".