I bought this 18mm strap: https://aliexpress.com/item/33044774071.html
And this tool: https://aliexpress.com/item/32976742331.html
I solved this problem by going on Aliexpress and ordering replacement metal band that fits the F-91w, A-158, and similar models. It costed $4.98. Been using it ever since and it works great. Being metal, now it's the least fragile part of the watch. You can also just upgrade to the ~$20 A-158, or one of the other metal band Casios, and get that out of the box. Timex also makes the T80 with a metal band as well.
I slightly prefer the light weight of the plastic band, but if you're okay with a metal band and your arm isn't too hairy (these low end metal bands like these can be painful if you are), then that's an option. The only tool you'll need to replace this is a spring bar tool that has the straight poker end or something similar.
There are plenty of almost-similar models, with the same low prices and some have standard lugs. The A158W is one of them. Then buy any strap you want, leather or textile are nice and cheap.
You'll want 18mm wide bars and straps.
1: https://www.amazon.com/Casio-A158WA-1-Water-Resistant-Digita...
https://www.amazon.com/dp/B000GAYQJ0
A158
Do you know the difference between the A158 and the A1000? And don't say it's 842 :D