The big issue with aluminum is it is hard to heat-work. Specifically, it does not agree well with torch wielding or solder joints. You really have to go for full-on inert gas arch wielding to get good joints. Newer electron beam wielding can work on lap joints, which most bikes don't use.
One thing lugged steel does have over aluminum is joint strength in the long term because aluminum does still stress fracture at welds when it does fatigue. But yeah, modern tig frames made of heat treatable alloys are also a thing now, but.... a bit up market from where I'm looking.
Notably, if you are going cheap, you can find a lot of old brass in the scrapyard. It is amazingly easy to work into rod metal with appropriate pressing tools. It also has low working temperature, wide working temperature, low brittleness tendency and can use simple hammer or rivet wields.
Oh you're talking full on frame building, I'm building up from a frame xD
In that case you just want to get some nice gently used parts and fix them up.
That's basically what my plan was, new for wear parts, second hand for 'perpetual' parts, even if with a preference for new old stock.
You can also get refurbished on certain parts. Fixing up wheels yourself may be beyond your capacity, but you can find performance wheels refurbished at a bike shop for deep discounts, and they will be good as new so long as you don't intend to treat them rough.
It's not beyond my capacity so much as I only just got a truing stand a couple months ago but that rear rim is definitely toasted after it got tacod. It's a significant reason to why most of my miles are on the trainer.
There is no way you could treat them worse than most athletes, after all.
Especially seeing as I'm pretty sure my FTP doesn't break 200 xD Never ridden with power or done any testing though so *shrug*
Most ebike systems are quite easy on the wheels.
ope *power meter
Wheels can be particularly tricky as spokes are a pain to balance, to the point that my brother gave up learning how to when he tried.
Ain't that the truth. I dished my rear wheel to run 2x7 (126 drop outs so it just fits) and keeping that cheap single wall rim true on city streets has been a hassle.
You can even hammer or rivet wield some alloys at room temperature, but it won't bond as well as when heated to full working temperature.