I often buy cash (and have to find people selling cash) to make various purchases

Luckily thanks to Bitrefill, and having spent the last few years orange pilling businesses in my local area, more than 50% of my expenditure is now done without banks (ie, debit cards) or banknotes.

People whining about not wanting to spend their sats are obviously holding fiat bags instead of BTC. It makes no sense anyway:

I think you hit the nail on the head. After a halving or two, you will realise the importance of, and want to spend, your BTC. You'll also be more likely to head towards the 0% fiat bankstering / 100% BTC savings goal.