These lists of things FE devs supposedly "have" to know never seem to include HTML, CSS, and JavaScript. You know, those things that actually are the front-end of a website.

They also tend to include a lot of solutions to certain problems. Problems that, depending on where you work or want to work, you may never encounter. There is loads to learn, but don't learn things because some dude on Twitter told you you have to.

It would be reasonable to say - with evidence - that certain tools are high value if you are trying to get a job in the industry. As long as that matches with the type of companies you want to work for.

In addition to core skills of HTML, CSS, and JavaScript if you are wanting to increase your general skillset I'd be looking at bigger pictures. Performance for example, being good at identifying performance issues and solving them is always going to be useful.

It's good to have a rough overview of what various things do, as then when you do hit a problem they would solve it's in the back of your mind. You can get that though by watching conference videos, scanning articles. You don't need to learn the thing to know what it's for.

If you've learned HTML, CSS, and JavaScript then I promise you, you can absolutely learn any of these tools when you need to. It will also be much easier because you are doing so with an actual reason to learn them, or a problem to solve.