Obviously, the genuine value is in M1, new or used, matters not-- no argument about it.
With that said, I am an idiot. Presently, I have located a couple of still-sealed 2017 MacBooks (new) and I plan to pick one up. I am gonna pay all the money. I already have a 2017 MacBook i5-16gb, 256gb and I keep my gear a long time. My advice, accounting for the traveling you hinted at and the MacBook 12 Inch; the alloy housing is subject to damage and it will damage easily. It is not hard to pick up a dent while in a backpack, covered or uncovered, it will get dented with daily traveling.
I dropped my 2017 last week and put a considerable dent in the corner. And as a result the USB-C port and internal DC jack now have an apparent alignment issue. I am having trouble charging the MacBook. The cable has to sit perfect in the port. Again, I could buy an M1, M2, or whatever but for me and my needs the Retina MacBook is a near perfect machine. Dollar for dollar it has been one the greatest devices I have ever owned. I run Apple Pages for income, utilise Safari for media consumption and email, that's about it. The speaker performance is a huge bonus btw.
Of note, the keyboard on the 2017s are unique to the model year but I am not so sure I agree with those who claim that the keyboard on the 2017's have been reengineered from the 2015/2016 offerings. As best as I can tell, only the iconography on the key caps has been changed. Further, with the 2017's the font on the display ('MacBook' is done in an old school apple font) has been changed and is slightly different from the font present at the bottom of the display on the 2015/2016 models.
Batteries are a genuine concern with the MB. My overnight battery drain (sleep) since Monterey has been insane. I blame Apple. Again, I don't run third party but there is a definite drain when in sleep. Apple has been a little sneaky about that sort of thing in their history before when trying to assist consumers out of old gear.
If it wasn't for you needing to be on the go I would say the 12 inch MacBook is a tremendous value on the used market but if your contacts or your work is linked to the machine and you're on foot -- get something with a more durable and thicker alloy body because the MacBook is paper thin. I dig it though. By this time next week a new 2017 should be sitting on the couch next to me. I am an idiot. hahhahahaa.
Cheers