Personally I don't like PHP so WordPress and PHP frameworks are out.
I find that Bootstrap is uselessly bloated, just learn css flex-box and you can do 95% of what Bootstrap offers (BS4 is built using flex-box).
Very complex: ReactJS, Laravel or Angular?
First Laravel is not an equivalent here, Laravel being PHP runs server side, whereas Angular and React are run clients side.
I don't think complexity comes into play here, the question is how much client side do you want/need to do for the given webpage/webapp. If all you are doing is serving a page with static information then you probably don't need to use and React/Angular or JS, stick with PHP (or what ever server side language). But if you want to build a webapp where the content is dynamic and constantly changing then you will need to use JS. Personally I prefer not to use any JS frameworks, just straight JS.
On the server I like Python, Flask or Bottle or some of the newer Async frameworks like Quart. I like coding in Python and it allows me to handle not just the web tasks but pretty much everything else, like the data manipulation / data science type tasks.
Another option to consider, NodeJS for the server, I don't have any experience with it but it is widely used, mostly in conjunction with React or Angular type applications (JS for both server and client side).
In the end no one can make this type of choice for you, it depends a lot on what you already know and are comfortable with and your willingness to spend time and frustration to learn a new language/framework.