Time (or lack theirof) has always been a problem for me. I've been very fortunate to have stayed employed through the pandemic but it's also wiped me out more than usual so it's even harder to get motivated to create things when I get out of work. Delays in shipping supplies have been a factor, but that aspect has affected everything for the world, so it comes as no surprise that it's affected prop and costume replication too.
Some supplies have been harder to source and pricing was a factor too. Thankfully, at least for me, things are starting to even out in this regard. I'd be very curious to hear other people's circumstances as well.