Drawbacks of Flutter for Web
Fewer libraries and smaller community
While Flutter’s mobile library ecosystem is vast with a great and helpful community, there are much fewer web app development libraries available. It means some of the libraries have to be adjusted to work on the web or even written from scratch.
The same goes for the community. The smaller the community, the less likely it is to find solutions to edge-case problems. But libraries and community are growing, and we can expect for both to be more reliable in the future.
For mobile there are multiple wrappers, plugins, but web Flutter is relatively poor (for now, of course). So for more complex projects (more on that later) there’s still some custom writing to be done.
Here’s a filtered list of plugins with web support for Flutter on an official pub.dev site. As of November 2022 there are 16,043 packages with web support for Flutter, against 27,781 packages in total.
Code regress risks
Regress — if one feature doesn’t work on Android you can change code, but you have to test how the change affected other platforms (web, iOS), this might require two separate code fragments responsible for the feature to ensure it works properly.
Underperforming search engine optimization — SEO
Because you’re building a web app, not a website, with Flutter, there are limitations in how much SEO you can maintain to ensure traffic to the product. But if you don’t rely on SEO for traffic, because, for example, the product will be an internal application for employees, then that shouldn’t bother you.
So your main company page with home page, services, or blog can be built using common HTML and JavaScript technologies to ensure the SEO aspect for marketing and reach purposes are met.
Little ability to customize
No ability to modify generated HTML, CSS, and JavaScript code.