When someone is trying to avoid the mistake of using a single wallet like before when the wallet was compromised through hacking and the option of distributing his risks by having multiple wallets that are independent of each other is not safe in your view, which option is safe? At least you should have added a better option and not just condemn.
Also, having more seed phrases as a reason to believe the option is not good is baseless. If someone can keep a seed phrase for a single wallet well, I don't see how such can't keep it well for multiple wallets and it is not new for people to have more than one wallet without any compromise. We've been sharing enough ways to keep seed phrases on this forum, if you don't know, you ask.
If you are already confident that you can store your seed phrase well, why would you need to use multiple wallets to store your bitcoins?
To me, there is no perfect and absolutely safe method, each method has its advantages and disadvantages. I should just say that in my opinion, using too many wallets is not as safe as you say, they also have certain risks.
You sound so perfect now, you who asked such a question, do you also have the guarantee that Bitcoin can't go below $50,000? Maybe you should read what I wrote again, my experience with trading/investment will never make me guarantee any decision, I can only speculate.
Against your wish, one thing I will not do is tell people to invest when the market is strongly bearish regardless of the investment approach you are preaching.
Have you checked the bitcoin price today? I don't have any advice because everyone will have a different investment mindset, but I would find it a waste to prevent someone from buying bitcoin at this time because the price of bitcoin is quite good to buy. At this moment, bitcoin price is trading at $59k while a few days ago it was just $53k or $55k.