Hello, hope you all are having a great day. so i am developing a wordpress premium blog theme to be uploaded to themeforest. and i wanted to ask that almost every wordpress paid theme on themeforest is developed using bootstrap cause i looked at most of the blog themes at themeforest and almost all of them say that its compatible with bootstrap 3.x or 4.x etc or it says build using bootstrap. but i want use Materialize for my theme responsiveness and design but i am hesitating because i wanted to ask that if i use bootstrap will it give me some advantage as its some standard here and if i use Materialize i will lose that advantage? and secondly what does it mean compatible with bootstrap 3.x or 4.x ? i mean i know what it means but why are they advertising bootstrap compatibility like that? i mean anyone can enqueue bootstrap in child themes if that’s the purpose of showing compatibility with bootstrap. i am sort of confused here as its not making any sense to me. please can anybody guide me that can i use Materialize framework instead of Bootstrap to develop a premium wordpress theme for themeforest and it won’t put my theme in any disadvantage what so ever compared to other themes…?
Actually no, there are no standard related using Bootstrap & you won’t loss advantage considering Envato Standards. It’s up to you using CSS Framework for your Theme.
It’s means, if you create your item with Bootstrap, you’re saying which version you’ve used of Bootstrap but Envato showing it to buyers so that they know which version of Bootstrap this theme used and they can hire someone with this version knowledge if they need any modification on this theme. Also it shows that the item used latest version or oldest.
Based on my understanding, I don’t see any harm to use other CSS Framework for your theme.
My view: most authors usages Bootstrap as it’s popular framework and clients will be comfortable with it because the can hire anyone easily with Bootstrap skill if they need to modify their theme. Otherwise it’s your choice to choose what tool to use for your creation as long as it follows Envato’s standards and policies.
Hope this answer will be helpful for you. 
Thank you very much, you helped me decide which CSS framework to use. thank you again
The CSS framework choice may be important when developing HTML template, but not so much for a WP theme. Majority of the buyers for WP themes are not coders, they won’t care about the CSS framework at all.
just one last question so i decided to use material design bootstrap or mdbootstrap at the end. but as you probably know mdbootstrap contains a lot of styling in there css with the !important keyword because i think mdbootstrap needs to override the original bootstrap classes cause they built mdbootstrap on top of bootstrap. as in envato theme requirement section they state that its strongly recommended to not use !important in css unless you have to. so will it cause any problems with envato theme requirements if i choose to use mdbootstrap or material design bootstrap? kindly please answer this question of mine so i could start developing and thank you for the support in this community
It is not only about Envato Requirements, !important is super bad practice which will make your theme much harder to customize and maintain in the long run. However, I have no experience with that framework. One, two uses of !important are fine I guess, but if it is full of it, then I would steer clear from it.