Be aware of the EABE pattern/attack which can leak information: https://monero.stackexchange.com/questions/12479/solutions-to-the-monero-eabe-attack . Avoid repeatedly sending exchange-received funds directly to a regular business without churning and changing your identity for the business

There are several cryptocurrencies which are regularly used for purchases. Just because BTC and meme-coins get the media coverage and speculation doesn’t stop others being used for transactions.

Hidden amongst all your bullshit (which Bobr has dissected) you do have a few reasonable points

barely handle the transaction throughput of Visa

Firstly that’s a non-sequitur, you don’t need Visa throughput to be a currency, but scalability is a genuine issue in the long term. That will need a 2nd layer technology, probably using sharding or other approach for more parallelism and throughput.

Monero is confusing for average people

Generally true. Any self-custody solution will be more complex than just trusting a bank service, but substantial UI improvements can be made and some trusted simple apps will develop.

Monero is centralized

There is currently a small group of developers and researchers, but they are distributed geographically and not connected except by their involvement in the project. All hosting and communication occurs on multiple platforms, including distributed ones like this one. It’s one of the most decentralized open-source projects around, certainly far better than BTC or ETH for example.

will not be allowed to be hard-forked

Bullshit, no-one can prevent hard-forks. Both source-forks and chain-forks can be created by anyone. That is a concern actually as bad actors can cause confusion.

community can’t decided unilaterally … technical stagnation

It will be the reverse. Unanimity or a centralized foundation would cause stagnation. Monero has had forks in the past, and it will have more in the future. That guarantees technical innovation. Customers will choose their preferred version. It’s a free market for currency innovation.

US hegemony is over. Get used to it.

How naive do people have to be to believe a political party when it reverses an agenda during an election campaign?

You should read about relatives trying to help victims of romance scams on reddit /r/scams. Generally its hard or impossible to convince some who is emotionally invested. I recommend you point out past BTC volatility and drops, and suggest he diversifies a bit if that’s all his savings. He could put some in gold, some in shares, leave some (maybe 50%) in BTC. He will still win big if it “goes to the moon”, and will have some protection from a crash. Often you need to make a mistake before you can learn this lesson. Eggs in baskets.