You don't need a company to get an ASN, but you do need to show that you intend to get network connections from at least two providers and generally that mean planning which plans are generally required as proof.
There are effectively no more clean IPv4 addresses, you'd have to buy addresses that had previously been used.
Anyone can get IPv6 addresses even those whose ISP sucks via tunnelbroker.net (aka Hurricane Electric) which will provide a single address, also a /64 and/or a /48. Of course they are generally blocked by streaming services since they are a form of VPN and thus the endpoint might be anywhere.
If I didn't plan on having a physical location (i.e., AWS or Colo as opposed to trying to get Comcast or any other connection to my house), what would constitute a network connection?
What are the terms of assignment via Hurricane Electric? Can they take it away? Do they only allow BGP advertisement to their sites or can I still bring the IP elsewhere?
I still think there is an opportunity for niche needs here.
At a colo or location of you own you might hire two upstreams like CenturyLink and GTT, and since your (purchased) addresses would be reachable via either you would need to announce via BGP which requires an ASN. At AWS the only provider is AWS and are typically single addresses (even if you special requested 256 you might not receive a /24), further I don't know that AWS will issue an LOA to allow to you to announce their space via other providers.
An HE IPv6 tunnel is as permanent as you like, but they reserve the right to phase out the terminal you are using which sometimes means your prefix would change, and they expire unused tunnels periodically. IPv6 has builtin handling of prefix changes though it does not deal with related DNS updates, which you'd have to arrange.
An HE IPv6 assignment is from their allocation so you'd call that PA not PI, i.e., you can't take them elsewhere. To get addresses of your own you would need to apply to an LIR or RIR for an allocation -- generally easy to get a /48 without any/much documentation with a /40 generally requiring documentation but that's not free (250/yr for an ARIN allocation).
There are effectively no more clean IPv4 addresses, you'd have to buy addresses that had previously been used.
Anyone can get IPv6 addresses even those whose ISP sucks via tunnelbroker.net (aka Hurricane Electric) which will provide a single address, also a /64 and/or a /48. Of course they are generally blocked by streaming services since they are a form of VPN and thus the endpoint might be anywhere.