Obviously, dust settles on flat horizontal surfaces, so having an air intake at the very bottom isn't optimal there. And yes, if the Mac stands in an office with daily cleaning, there might not be much dust, but still, if you run it for 5+ years, it will suck in a lot. If it is in a corner of a small desk with lots of other stuff and not daily cleaning - e.g. at home, there can be considerably more dust.
My MB Pro started failing for thermal reasons after 5 years, fortunately, the local service partner could clean it for a tip. After that, the thermals of the machine were distinctively improved.
Dust in the ventilation is just a matter of time, a machine should not fail because the user can't clean that dust.
I live in a fairly dusty environment that also gets quite hot in the summers. I have to clean my i9 16” MacBook Pro’s cpu fan and heatsink every 3-4 months or else the CPU starts throttling. The MacBook Pro is relatively easy to clean. You just need to know how to remove the bottom cover and the fan plus heating assembly is east to access. But it used to be much easier with the older models. This Mac studio’s design makes it very difficult to clean the heatsink and fan blades. Also the heatsink looks like it has lots of thin narrowly spaced fins, something that will get clogged up really fast in a moderately dusty environment.
I hate to break it to you, but there's not a PC / laptop on this planet that will not fill up with dust and eventually clog and die. You gotta keep your stuff clean. Blow it out with some compressed air cans every 6 months. It's not really that big of a deal. I've cleaned literally thousands of computers in my lifetime, they all get dirty, and if you don't clean them, they will all fail.
Also, I think you are way overstating how dusty this will get. It's not going to be any worse than anything else built in the last 20 years.
My MB Pro started failing for thermal reasons after 5 years, fortunately, the local service partner could clean it for a tip. After that, the thermals of the machine were distinctively improved.
Dust in the ventilation is just a matter of time, a machine should not fail because the user can't clean that dust.