If you write the seed phrase in a special book and are afraid other people can access it, you can use tricks like changing 1 or 2 positions of the words. That way, even if someone steals your phrase, they can't access your wallet. (You just need to change the position of the two words, no need to change too much to confuse yourself).
Backup your wallet seed as most simplest as possible but make sure you store your backup safely and avoid eyes of other people.
Don't try to trick others and consequently trap yourself with a risky backup method. Changing positions of 1, 2 or 3 words in your wallet seed is a terrible idea. You will need to remember it, need to have a note for these positions but if you lose those position order by a memory loss, note loss, you will need luckiness to recover your wallet seed.
How to back up a seed phraseYeah, you can care about it on the long term and if you are careful about it then you are going to end up with something much better. Simple stuff like writing it down to your notebook would be simple but effective for many cases.
People talk about things like "what if there is a big fire, what if there is an earthquake" and so forth, well if you want it so much then put it on an exchange and as long as you memorize the mail and password you use, you can login from anywhere in the world, of course have access to your mail as well. But if you want more security, then ignore the one in a million chance of fire burning down all of your house, and just go write it down to your notebook and be fine.
You're right, everything has pros and cons, nothing is absolutely safe. If we keep making thousands of hypotheses and thousands of reasons, we will never find the final solution for ourselves. Maybe one person's method is not suitable for another, but as long as it brings them safety, there is no reason for them to change or imitate others. My method may have risks that others consider inappropriate but for me it's been fine so far. And there is no guarantee that if we follow their method, our seed phrase will remain safe.