I'll prob. be downvoted but here's my honest opinion: I think you'll gain a lot career-wise to learn about UX and UI. You'll be able to understand products in a deeper level from the customer's side and will then be able to make better decisions as an engineer. You'll also have a much easier time working with designers and PMs. And, of course, your projects will feel and look great.
IMHO, the biggest bang for the buck you could learn is:
- Visual hierarchy (I.e. the same way you divide your code in modules and functions, you need to divide the visual space in a clear hierarchy).
- Basic on typography (It makes a big difference even if most people don't notice it)
- Understanding what's UX (I.e. reading "Don't make me think"). Just "caring" and "thinking" about UX will improve designs, even if you don't have much experience.
- Basic of color theory; How different colors mean different things (Branding-wise or for alerts/errors/warning).
Reading material design from Google https://material.io is a great start. You may not like the UI of it, but the UX and explanations of why things are this way are really interesting.