All things equal, does running a WordPress site add a lot of bloat compared to running an HTML/Bootstrap Framework site?

Many Wordpress themes currently use Bootstrap WITHIN them, so it’s usually a given that such sites will include more front-end bloat because there are at least a handful of default scripts, specific to Wordpress, that need to be loaded around that. But… it’s still possible to keep a Wordpress site very lean by finding or building a theme that does NOT use a CSS framework as large as Bootstrap and instead uses a lightweight grid system without the extra fluff. In that case, the Wordpress site would have the advantage out of the gate.

Beyond that, it comes down to the number of various plugins that are installed in the Wordpress theme. Some plugins add quite a bit of bloat because they are offering a lot of pre-packaged functionality, only a small amount of which the developer ends up using. Some of these plugins may call heavily on some of the same Javascript libraries or API’s that you may decide to use in your “pure” HTML/ Bootstrap site. So generally, it still comes down to what you decide to do with your site.

Rarely is speed the only important factor in deciding how your site should be built, so be sure to make your decision by looking closely at the project requirements and weighing all of the benefits that Wordpress offers.

Of course it does.

But all things are not equal, and they never will be.

An HTML/bootstrap site is an ideal site for certain specific purposes. These purposes might include a basic professionals presence site (a doctor, a lawyer, an architect, for example) whose function is to be nothing more than an online pamphlet and business card. Such a site is designed, on discussion with your client, so that it is not going to be updated, it does not need to outperform competitor sites, it does not need to provide any functions other than basic information. Your clients primary intent is to have a site that NEVER GETS HACKED, and that is utter;ly stable year after year.

That’s a perfect use for an HTML/bootstrap build.

And it is a scenario that is becoming rarer and rarer.

From the picture of function and purpose I just drew, you can extrapolate the type of uses for which an HTML/bootstrap site might be considered. Static. Rarely needs to be updated. Stability and security and the lack of need to be monitored or operated. (that is, it is cheap to keep up over the years.)

If you want to compete in the search engines, if you want a website with visitor interaction, if you want a site with steadily growing content, a site with which to promote an active business that sells or services the general public, in almost every imaginable case something like WordPress will be your first choice.

Your only real choice. Every other possibility has now fallen substantially behind.

Why? Because the clients have come to expect the WordPress experience and WordPress functionality, and only a popular open source software like WordPress has the user base to keep up with the constantly changing internet environment and expectations.

There are a few exceptions. But if you were dealing with those exceptions, very advanced web development, you wouldn’t be asking about WordPress in the first place, you’d be asking questions about scaling.

I'll piggyback off what Chris Prakoso said.

Both start with very little bloat but could quickly get out of control in different ways.

For example, on an HTML/Bootstrap site, you could fill it with images that aren't optimized and tons of additional Jquery libraries. On a Wordpress site, you could add tons of plugins that really weigh the site down.

We haven't even talked about how you can use an HTML/Bootstrap Framework to create a Wordpress theme.

Point is, it's all about balancing what makes your site cool with what makes your site load quickly no matter what it's built on.