I agree with everything in your post, and we are in the same side. But for the plebs' sake, especially for someone very new to Bitcoin, I won't recommend them to risk tainting their coins if they merely want privacy for the sake of privacy. That's just practically speaking ser.
Here's the problem with that, though: The more people who buy in to this "taint" nonsense, then the more powerful it becomes.
For that we have technologies available to keep Bitcoin fungible.
No no, now you're again trying to 'exchange tainted coins for untainted ones'
using technology. I use mixing and LN to cut ties in payment links, but be assured that in the future, the most 'tainted' UTXOs will be those coming out of mixing services.
The whole 'taint community' (governments and their friends) will tell you those, as well as Lightning funds, are all tainted, because it's not sure that they come from a 'good, non-criminal origin'. Their goal
is not fighting criminality.
You're right! The taint community can simply say that all coins coming from "Service A", or "Off-chain Layer B" are all tainted! But talking about fungibility, what's the practical solution if they can even say that all Monero coins are "taintcoins".
If you compare the amount of crime conducted through BTC vs what is done through fiat, it's laughable. It's all about control. The authoritarians' preferred way for you to use Bitcoin is buying it in a KYC exchange, leaving it there and selling it later. At most, they want you to transfer it to a wallet and back into the exchange; they are trying to undermine its usage as a payment system entirely; especially if you introduce something that makes tracing harder.
I know! They're making criminals of ordinary people/plebs. But the cat is out of the bag, Bitcoin will enter gaps in markets, and especially where it's truly needed.
That's why Wasabi changed course after being pressured by 3-letter agencies and now only mixes your inputs if they are 'untainted' (probably in the future only the case if coming directly from a centralized exchange). They will also surely give in to those agencies again if pressured and log mappings between inputs and outputs and provide them in case there was potential 'illicit activity' detected.
For simple untraceability/privacy without problems, I would recommend Wasabi to newbies for porn subscriptions or sex toy purchases that they want to hide from their wives.
There is no technical solution to this purely political problem. We have - as o_e_l_e_o said - to stop buying in to this "taint" nonsense.
I agree, and I have debated that taint doesn't exist in the blockchain. Plus that's why it's important that most of your Bitcoin that were converted from fiat should never be converted back to fiat. It's a practical solution.