I would have said the same a couple years ago, but nowadays I can get an external 5TB solid state drive for a few hundred $$ that easily fits in my laptop case. As long as my OS runs from the internal disk, I don't really need much more. Everything in the cloud anyway. :)
My concern is more with the longevity of the drive. SSD failures are only a matter of time, and these new Macbooks are going to be bricked once they hit their TBW limits.
I have no idea why you're downvoted. This is absolutely a valid concern and one of the biggest reasons why I'm staunchly anti-Apple.
There’s a very good chance that the MacBook is outdated or otherwise broken by the time the SSD fails. I’ve been using SSDs for about 10 years, and I’m not the heaviest user, but so far I’ve never had an SSD fail from wear. Thumb drives, sure, but not SSDs yet.