No surprises here. Just like the lockdown on iPhone screen and part replacements, Macbooks suffer from the same Apple’s anti-repair and anti-consumer bullshit. Battery glued, ssd soldered in and can’t even swap parts with other official parts. 6000$ laptop and you don’t even own it.
You may want to check out these two videos from Louis Rossman. He talks about your exact problem with the soldered SSD and directing you to drive savers.
https://youtu.be/OVZTBhVV5tI
https://youtu.be/0qbrLiGY4Cg