The new Mounts of Mayhem drop/update has not fixed my issue either. It crashes when the skin and or marketplace load.
I am having this issue only on the latest update. Has been completely unplayable for weeks so i can’t play on realm. Here’s a video of what it’s like on my end.
To fix this bug on my end i went into appdata / roaming / and then just removed every folder that related to minecraft (99% sure the only one you have to delete is the “Minecraft Bedrock” folder) including emptying my recycle bin. After that i ran “wsreset” in windows run and loaded up “Minecraft for Windows”. I recommend backing up your world files beforehand just incase.
I also think that another possible fix that worked for others is to login + download minecraft on a different device such as a laptop or another pc and use the newly created files on the spare device to replace the ones on the bugged device.