Protecting items (particularly a handy haversack) from destruction

[Darg]

I sell my bags of holding and buy enveloping pits. They're extremely inexpensive (3,600 gp) and are essentially 10' x 10' x 50' portable holes. I'd use a handy haversack for anything I need to keep around, with gloves of the master strategist for anything I need at hand ASAP.

Right, you just buy relics. Makes sense. Relics are as common as normal magic items.

Whenever I have the money when starting a game at higher level, I'd do this.

If your DM allows you to do this, good for you.

I avoid leaving my stuff lying around. There are tons of ways that could go badly, no matter where you are or what you're doing. Every ecosystem in D&D is filled to the brim with hostile sapient life and lots of critters that love to steal/eat/destroy shiny magic items. I ain't riskin' it.

Sounds like your DM is compensating for how far off the rails your games are.