I've switched to only buying SD cards from AAA+ platinum-rated photography websites (B&H, Adorama), they seem to be the only reliable places to buy non-counterfit SD cards these days. I've never had an issue with an SD card since I made this shopping change. Shipping and price are about 10% higher, but guaranteed quality product is worth it.

If you buy your SD cards from Amazon or Ebay you can't guarantee quality for these products.

What SD brands do you usually buy? Are the Sandisk Extreme range any good?

Sandisk, Lexar, Prograde. Depends on the application.

My raspberry pi doesn't do many disk operations so the speed isn't critical and 90 MB/s is plenty. My digital camera, on the other hand, has dual SD card slots, and can record uncompressed(!) 10 bit 4k video @ 60fps but needs 2 x 400 MB/s continuous write, which is... a pretty specific need. And cost accordingly.

I find Samsung much more reliable than Sandisk in my pis

Sandisk makes high endurance microSDXC cards, e.g. SDSQQNR-064G-GN6IA, which are inexpensive. Beyond that, they also make industrial SLC microSDXC cards with very specific longevity guarantees, e.g. SDSDQED-064G-XI, but those are rather expensive.

M.2 is possible on the compute module, but there's iirc only a single PCIe lane on the pi... so it's not as speedy as desktop and also you'd need a PCIe switch to get M.2 storage and networking/USB which just increases costs further and in the zero's case, probably not possible with board space.

pi3/4 can boot straight from USB.

In my case.. I have a couple of old gen1/1.2 Pis, no boot straight from USB, but an SD card with only the FAT32 /boot partition that's got the read lock on card set, and boot config set for a USB stick in the side of it. They're still slow, but not gonna brick the SD card.

Am using (high quality) USB for my pi storage now. Recent firmware can boot directly, though before that I was using the sd card as boot partition only, having everything else on USB. Depending on the application, network boot (i.e. completely diskless) might also be an option - probably the most reliable one, but needs wired ethernet so not possible on the Zero.

Three options:

1. Use an "endurance" SD card, these are usually advertised for dashcam use.

2. Boot from a USB device instead of SD, now natively supported.

3. Boot from LAN, also natively supported.