But why do people buy the M Pro if a standard M is all they need? Why buy more memory? Are you sure a Logic recording studio doesn’t need a Pro chip or more RAM?
Because "Logic recording studio" is as long as a piece of string.
At one end of the scale, MIDI sequencing is 1980s tech, digital audio recording is 1990s tech, a CD-quality stereo audio stream is about 1.2 Mbps when even old-fangled USB2 is 480Mbps. Logic first appeared over 30 years ago -
although at the time yiu needed a "massive" 600MB of disc space!!! - and the bandwidth of the mk 1 human ear-hole hasn't changed in the meantime.
70 minutes of high quality stereo audio, uncompressed, fit in less than 1GB of storage or RAM - you might want to double that if you want some headroom for mixing and effects, but if you think you can hear the difference I've got some special green CD mats and audiophile ethernet hubs to sell you at $500 a pop.
The processing, RAM and storage specs of modern computers are largely dictated by video editing and 3D graphics which are an order of magnitude more demanding than audio work. The cheapest Mac and many iPad models are more than powerful enough to do the basics. VSTs and effects can be quite CPU heavy but they're only working on a few dozen milliseconds worth of data at a time so they don't necessarily use that much RAM. Of course, there's the obligatory elaborate 3d-animated control panels...
At the other end of the scale,
there's this guy who wants
all the samples for a 100-piece orchestra cued up in RAM,
and has a workflow that involves running Pro Tools and Logic simultaneously, and apparently needs a Mac Pro with 700GB of RAM. Guy's got an actual flux capacitor in his Eurorack so I'm not gonna second-guess him

However, it depends whether you'd call that a "recording studio" - he's a composer and clearly doesn't want to break the creative flow every time he wants to load up a new instrument.
In short, you can probably record a 4-piece band and add a bit of reverb and EQ with the cheapest Mac or most iPads, although getting an 8GB RAM/256GB HD with that task in mind would be false economy.
But, if you need hundreds of effect-loaded tracks you're probably going to want a more powerful CPU for those plug-ins just as much as more RAM. At the higher end, the scarcity of RAM on Apple Silicon systems - both the insane prices Apple wants for upgrades and the physical limits on how much RAM each SoC can drive - are a problem. I suspect that optimising software to take better advantage of super-fast SSD would fix the "pre-loaded samples" thing & that the requirement dates back to the spinning rust days, but that's down to the software developers.
The Mac Mini in my studio gets moved very rarely, only when we need to change what’s plugged into it the back. That’s why people forget about the power cord possibly being stuck on something and pull it forward too hard, crashing it like it’s 1999. That is always disrupting and can be devastating, destroying you reputation as a studio.
Then
get professional and fix your cable management. Get a $5 pack of cable clips and fix the mains and other cables in place with enough slack to let you pull the Mac forward. Get longer cables where needed. Get a USB hub or USB switch or set up a patch panel so you have front facing sockets and don't need to move the Mac. Put a big yellow "do not move this while the recording light is on OR ELSE" label on it.
Professionals don't move or mess about with cables on live equipment that could be "devastating" if it crashes - and while a battery might fix that for the mains cord, it won't stop disruption from (e.g.) unwittingly unplugging external storage or networking. Pulling a mains cable like that
once is human error. Doing it again is unprofessional.
You're fretting a lot about how laptops "look unprofessional" - hardware isn't professional or unprofessional, people are. I don't care if an electrician does my wiring with an Amazon Basics screwdriver. I do care if they're careless, work in a dangerous mess, keep accidentally pulling out cables, need me to explain the wiring diagrams to them, use 1" of 5A wire to extend a 30A ring main wire that they've cut too short*... er, sorry, getting too specific there
(* it was pretty crispy when I found it... never met the person who installed it so I could shake them warmly by the neck...)