I’d say no. Your fooling yourself if you think you can. The best you can do is make it harder, but that is only true compared to computing power. Problems that were hard, are now possible because computing power has increased.

Any one profile could give enough to out you. A textual analysis can tie separate text posted by different accounts to the same person. (Varying degrees of accuracy for this. If anyone would do parse all Lemmy comments to do this is separate issue.)

In short, don’t post anything that might compromise you. But how fruitful are conversations if you’re always hiding anything that might out you? Stick to only non personal stuff? Information about local shops, movies, etc etc can all narrow down your location. But even with that, narrowing down to a town with 50 people in it, is different to a town with 1 million people.

It isn’t only what you post. Someone else can also out you. Someone who knows you, or someone that you don’t know. Your PC can be hacked, etc etc. The options go on and on.

Define what your risk is. Define who your adversaries are. Then plan how to operate with acceptable risk tolerance.

Nobody can anticipate all risks

Then stick to “don’t be online” as you no matter what you do, you can’t anticipate how that will expose you later.

There is no privacy online. Enough incentive your history across accounts, instances, usernames can be combined.

Think about risks instead. Who is going to use your post against you? How much effort are they going to go to? What’s your risk?

If you’re hiding from the a government, best not to be online. If what you post will get you killed, don’t post it.