the next best thing is hard to predict, as thre sister comment says. it's also not an important measure. the measure that matters is wheter a framework is going to stick around and be supported for the next few years.

to choose a framework look at all that are being used and recommended.

for every recommended framework there are a dozen that remain in obscurity.

that should narrow it down to a dozen or so. look at each and pick on you like the most by whatever metric you prefer. it does't matter.

keep using that same framework as long as you are happy with it.

if you are able to stick with the same framework for a few years you made good choice.

as for svelte, one metric is the stateofjs survey, which lists svelte as one of the top 6 frameworks.

it was added to the survey last year which shows a significant amount of interest. let's see if that is still true next year.

https://2019.stateofjs.com/front-end-frameworks/

my own choice, aurelia, which i picked a few years ago, is the 3rd most write-in choice. it has a healthy community and active development. and i see no need to change for the forseeable future. it doesn't need to be the next big thing.

I don't think this is clear cut. React has been around for more than 6 years. According to the latest State of JS survey[1], 72% of respondents have used React before and would use it again. That number is 7% for Svelte.

Svelte has a lot of interest, but it also has a very long way to go against a popular, 6 year old project.

[1]: https://2019.stateofjs.com/front-end-frameworks/

React was like this for a long while too, compared to Angular.

Then once some big "used in production by NYT/x/y/z" hits, a premier conference talk, then things explode with everyone virtue-signaling how they use the modern/best stack, floods of article/blogs are posted about how they switched over before you did, and the FOMO cargo cult bandwagon rocketships.

Svelte does look legit, but it is better to not buy into the JS virtue culture.