If you're serious about doing web development, there are lots of reasons to NOT use Elementor or any similar plugins, like Beaver Builder, Thrive Content Builder, Visual Composer and dozens of others.
The first problem is all these plugins are (obviously) web-based. Web technologies have come a long way over the past few years, but anytime you're doing live editing over the Internet, your efficiency is limited by the speed of your Internet connection. If you have a stable and fast connection, it may not be that noticeable, but it will never be as fast as a desktop application like BSS. When I'm editing a web page, I often try out a bunch of different layout concepts and it's frustrating to be slowed down by my Internet connection.
The next problem is these tools completely disable the built-in WordPress editor and replace it with their proprietary interface, This means you no longer have access to the HTML code for your web page. Most of the time, this isn't a big problem, but good luck doing anything custom, that falls outside the parameters of the editor. A more important consequence is that your website becomes dependent on the plugin. If you disable the plugin, the page will no longer render. Instead you'll see a bunch of programming code, WordPress shortcodes, etc... This is because these plugins don't store the page as HTML, they store it in their own proprietary format, which gets converted to HTML on-the-fly, each time the page is viewed. This is problematic because software companies come and go like the wind. Plugin developers are constantly going out of business, being acquired by other companies, or sometimes they stay in business, but start to neglect their product. After a plugin has been neglected for a while by its developer, customers start to look for other alternatives. Inevitably, you find a new plugin that you like better, but since neither the original plugin, nor the new plugin store the page as HTML, it's extremely difficult to transition to the new plugin, as there's no simple migration path. You'd have to start over from scratch, manually re-building each page in the new plugin. By contrast, BSS exports as standard Bootstrap HTML, which can then be pasted into the built-in WordPress editor. Thus it's compatible with any editor that supports HTML, including the built-in WordPress editor. If you ever decide you want to stop using BSS, you can continue editing your page content in the WordPress editor.
Another downside to WordPress plugin editors is that none of them are Bootstrap-based. Instead, they all use their own proprietary frameworks. Since Bootstrap is the most popular front-end framework, there are massive amounts of resources available to enhance Boostrap development. When you work with something like Elementor, you're locked into the Elementor ecosystem, which is minuscule compared with the Bootstrap ecosystem. Also, if your WordPress theme is Bootstrap-based, the code you export from BSS will be fully compatible with the theme, since it uses the same framework. Conversely, if you use Elementor inside a Bootstrap theme, the results may be unpredictable. For instance, you may get strange results when you scale the page down to a mobile screen size, since you're literally using two different frameworks on the same page. Some of these effects may be subtle and perhaps many people wouldn't notice, but in my view, using multiple frameworks on the same page is sloppy and amateurish.
Finally, I want to state that BSS is a GREAT editor. The developers have done an incredible job creating this product, which in my view is far superior to Elementor or any other WordPress editor plugin. For this reason alone, I'd prefer to use BSS when creating my WordPress content areas.