I don't think there are masses of episodes out there, but more than we would probably think there are.

I also don't think it is a refusal to share, I think it's morelike Uncle George had a couple cassettes stashed in his attic and it is just sitting in storage and no one even knows they're there.

I think it's very unlikely that someone with a complete, decent quality lost episode is just sitting on it. It's more likely that any existing tapes are poor quality, degraded, or partially recorded over. Or even that the hardware to play it back doesn't exist anymore.

IIRC, Betamax came out in the late 70s, and equipment before then wasn't really home-use friendly. Not many people had the equipment to record, much less the luxury of keeping the recording for the long term on expensive media.

I remember something about Web of Fear episode three, the episode that actually introduced Lethbridge-Stewart, and how Morris had the whole serial but before he turned them over to the BBC episode three somehow vanished.

There have been credible claims of a handful known to be out there with collectors, in particular Web of Fear 3 seems very likely, it would likely be a number in single digits if there are any. The problem here is that it says there are 97 missing (true), but then could be taken to mean all of these are missing because collectors have them. Rather they are all assumed to have been destroyed, but it is possible a small number escaped that fate and are still out there in the hands of collectors

People replying seem to think that this is referencing someone who recorded the episodes on their VCR (in the 60's?) and have a stack of tapes in their closet.

I think most of the recovered episodes have been found in foreign broadcaster archives in the form of 16 mm film. I would guess that is what they are talking about. Either some dusty film archive in some country somewhere, or some personal collection where someone who lifted the film from their employer has it stashed away.

However, I also think it's probably getting more and more unlikely that anything more will be found.

From https://wikipedia.org/wiki/Doctor_Who_missing_episodes:

"Most Doctor Who episodes were made on two-inch videotape for initial broadcast and then telerecorded onto 16 mm film by BBC Enterprises for further commercial use."