In most cases concerning the theft of bitcoins, it's the user who made one or multiple mistakes. The problem is, people don't want to admit making mistakes, not to themselves and not to others. It's always something else that caused it.

Everything you do on that computer can potentially be a landmine because that's what happens if the device that holds your keys is constantly online and used for various other activities. You need to separate that. Getting a hardware wallet is the easiest way. Getting a second laptop with a genuine OS that you aren't going to use for other things online is another way. Using a completely airgapped solution is the least user-friendly but safest option.