I've read from people here saying they had great productivity gains and simplicity using these options.
There are many options though with quite a bit of differences and I wanted to hear from people who have evaluated some of them and what they settled on.
I have a previous experience with VueJS and Django REST Framework. It is nice but it's a whole other kind of work. Too many build tools, CIs, State Management hell...
I'll, if I can, keep developing with the new-new stuff (Unpoly and htmx). Probably won't be 100% of the time since it's far for mainstream technologies.
Definitely not "zero" JS, but our JS interop source file is only ~200 lines of code at the moment.
We have some incredibly complicated UI interactions (essentially canvas drawing) which would be a nightmare to synchronize state for. Being able to keep all that state server-side makes it way easier to cope with. Our clients are basically just a dumb terminal on the other side of a websocket.
An example of the DSL in htmx I mentioned (from https://htmx.org/docs/#validation):
To me this reinvents a subset of js (and compiles it down to js), event handlers, etc. If you just need some inline behavior just use the on* attributes that are in html and if you need more then write a js file and if you need even more use a framework.
I don't think it solves every problem efficiently, but as SahAssar mentions (with some thoughtful criticism) below, as your needs become more complex, the framework provides at least some kind of escape hatch into more traditional programming, admittedly strange though it looks embedded as a DSL that gets put into an HTML attribute.
On the other hand there are some cool behaviors that I've leveraged to great success -- in the responses you return from your backend that HTMX is interpreting, you can encode data into headers that HTMX will turn around and trigger as DOM events. Pretty neat way to interact between your front and back-end both on a DOM and a JS runtime level.
I've worked with Livewire quite a bit and think it's a brilliant concept. It's very easy to get started and you get great results without much training.
However, as soon as you encounter problems or want to implement things that deviate from the standard case, you quickly realize that this is a new technology. There isn't a solution for every problem on Stackoverflow and apart from the official documentation there is very little good information.
So for complex apps, it's often better to go with VueJS which has a better and more comprehensive ecosystem. The great thing is that Inertia.js exists as a link to Laravel, so you don't have to build an API and you don't have to worry about things like routing or authentication.
[1] https://laravel-livewire.com/
Edit: Add more background
So you can totally make an application only with server side technologies because it was how we did before and… it just worked. What is interesting is that all the frameworks, due to their age are very mature.
If you are ok with Python, I suggest you to go through the official Django tutorial, it’s pretty long (some hours iirc) but it covers a lot of topics by guiding you through the development of a complete application.
But other frameworks like Rails, Symfony, are also very mature. ASP.NET Core with Blazor is also nice but IMO, harder for a newcomer because it needs a lot of boilerplate.
All those technologies are pretty boring, but in the good way: they allow you to get shit done without thinking a lot about technical issues.
So since two years, I use the Hotwired stack on top of PHP (and now with Vite as bundler) and that is so far the best solution I found. I can like use the CMS integrated solution for handling forms, as an example, but can plug in Hotwired Turbo and some Stimulus controllers when I want things to happen async on the client. I now have my own set of generic stimulus controllers I reuse in every project. But at the end of the day, those websites work without JavaScript.
I recently took a look at Hotwire and Unpoly just to make sure I wasn’t missing out on something better. I found htmlx simple and intuitive.