This doesn't seem to be targeted at the frequently-swapped use cases that SD cards are made for. It's more about adding repairability/upgradability to internal primary storage in small devices. For that use case, the 4x throughput advantage is probably reason enough to rule out SD Express.
I don't think the connector is the problem but the devices you connect to. RPis are notorious for having a poor lifespan due to reading/writing from the SD cards, but I think that's mostly due to the cost tier of a $30 computer.
> RPis are notorious for having a poor lifespan due to reading/writing from the SD cards
How does the Raspberry Pi deteriorate from the interaction with the SD card?
I'm running a batch of SBCs which boot from SD cards as home or forgettable servers. None of them died due to SD card failure yet. A good SD card with a little optimization keeps the flash media wear out at bay.
What little optimizations?
Like writing logs to RAM and syncing back to disk daily or only on reboots/shutdowns, keeping high-write applications on a USB drive and providing the biggest cache possible by slimming down the OS memory footprint.
This two things reduce the hits to SD card substantially.
It has more to do with the garbage $2 power supply someone had "lying around".