Surely you are capable of replacing a car battery. The main point is that a phone battery should be mandated that it is easily replaced like a few years back. Likely a laptop battery could be similarly done if Apple was foreced to make it so.
To be fair, although I'd be quite capable of replacing a car battery and have done that (and more) back in the good old days (when I pretty much knew how the power & ignition system worked) - by the time I'd collected a new battery, found the right spanner, skinned my knuckles, sprained my back, then found somewhere to properly dispose of the old battery... I'd rather pay someone to do it who had all the right tools lined up ready to go
and knew what to do if the fancy modern engine management computer needed counselling to get over the trauma.
Yes, some people would prefer to service their own car - but they're usually prepared to invest in tools and equipment (or have a mate who's workshop they can borrow of a weekend). As far as the tool purchase/hire part of the Apple scheme is concerned - I think that's more appropriate to enthusiasts or small businesses who might buy the tools permanently and have fun/make pocket money fixing their friends' Macs and iPhones.
...also, I think the battery in my car is currently about 12 years old and still going strong - and the
real reason I rarely open the bonnet is that I rarely need to, because modern (i.e. this century) cars just don't go wrong as often as they did back in the good old days. (OK, I've probably jinxed it now!)
Also, you can't ignore the fact that the sort of lithium batteries you get in modern laptops are little incendiary bombs just waiting to go foom if they're damaged - esp. if you're replacing one because it is already faulty. Sure, you could drop a car battery on your foot, get a shock or a burn or get acid in your face but it takes a special effort.
If you want an easily swappable battery in today's MacBook Air, expect it to be much thicker or have a much worse battery life since the battery would need to take the old form factor to be easily removable – and thus have less space for power cells.
Partly this - although I do think Apple could have sacrificed a millimetre or two to avoid gluing the battery into the top case. My main beef with Apple is not so much that I can't repair stuff myself, but that you have to pay to replace so many perfectly good, expensive parts that the perishable parts are glued to.
If you look at something like
the Framework Laptop - designed to be upgradeable and repairable - its a perfectly viable product but it's
not MacBook slim, doesn't have cutting edge performance or battery life, no LPDDR RAM on the processor package for max performance etc. and even if you upgrade it that's
still going to leave a trail of M.2 modules, DIMMs etc. for landfill. Environmentally, it's probably better to hand it on as a working system. Some people's MacBooks never leave the desk so it won't matter if the battery can't hold charge...
Question is, if Apple did produce something the size of an old ~2010 MacBook with replaceable battery, upgradeable storage and slower/power-hungry DIMM-based RAM, how many people would vote with their wallet?
The only old machine I've
extensively upgraded is my 2011 17" MBP - which got a mid-life RAM upgrade, new SSD and the optical drive replaced with the original hard drive... and that was only
really compelling because even an affordable SATA SSD was a vast improvement over a mechanical HD. Usually, when a machine has been obsolete, every last component has been ripe for replacement, save for a few tower PCs where the case has got re-used.