Recently I changed jobs and moved from being a front end dev to a backend dev role. Less framework chasing, more architectural concerns / long term planning, slower pace of development / expectations from stake holders and double the pay. For reference: I used to do backend dev but I did FE exclusively since 2016.
The problems seem to be harder on the backend, henceforth more challenging and interesting. Also optimizing code for AWS directly contributes to the bottom line of a company. So if you save $10k a month because you optimized some service, it's more likely to be rewarded.
Optimizing web pages make page loads faster, but doesn't necessarily contribute to the bottom line.