Please read and check the points from 5-9 I shared. It doesn't matter how fast are your website pages and hosting, if you have the problems listed from 5 to 9 then your forum pages will be slow and that's not wpForo issue.

wpForo is a very lightweight and fast plugin, if it would be such a slow plugin we'll have hundreds of reposts. Almost all reports related to the slowness were the website specific issues. I'm sure yours is also the website specific issue.

So this means that my host is fast, my cache plugin is fast and there are no known clashes with plugins. Also gravatars and signatures on the forum should not be an issue because even threads with JUST ONE POST load slow. Here is proof https://pagespeed.web.dev/analysis/https-www-paradigmshift-com-pk-community-forum-job-search-forum-police-assistant-jobs/7wyvm22psk?form_factor=desktop (46 on mobile and 65 on desktop only). Super bad.

So all the forum pages are slow. Secondly, your own forum is very slow (please watch my video below). I checked your PSI score for the community page and it is not good https://pagespeed.web.dev/analysis/https-wpforo-com-community/5yz4zc51jv?form_factor=desktop

Check my psi score for my forum - it is even worse.

https://pagespeed.web.dev/analysis/https-paradigmshift-com-pk-community-forum/ka6ijq4vk1?form_factor=mobile

If wpforo's forum pages were fast themselves then I would agree with you that there is something wrong with my website only.

So there is definitely an issue. Here is the video again to prove it (PLEASE watch it because it proves what I am saying) I have sent it 3 times and none of you have seen it.

https://streamable.com/672yhs

Thanks!

There is no slowness issue with wpforo for sure. In most cases the problem reasons are the following:

1. Hosting service issues
2. Attacks to the website
3. Database optimization issues. Mostly the table indexes, optimizations and repairing.
4. Damaged data in the database. Something could be corupted in the database that crash SQL requests or make them very slow
5. Conflicts with other plugins. Some plugins could conflict with wpForo and make a lot of problems  through WordPress hooks
6. External content in wpForo pages. Some users may have avatars with external URLs that laods very slowly. Even the Gravatars can make the wpForo pages very slow. You may have many users using Gravatar or the default one is very slowly loading.
7. External content in users signatures or in the post content (videos, images and embedded iframes). 
8. WordPress Theme configuration and issues with the forum page.
9. Disabled wpForo cache or cache conflicts with hosting and WordPress cache.

There is no way to understand the reason of your page slowness by discussing in this forum. This requires a deep debugging directly in your website and server. Unfortunately, this is out of the free support scope. You can do that yoursalfe going through the list above. You can find some WordPress expert to check your system or request for wpForo Pro support. 

"We may suggest you use the following code:

remove_filter('wpforo_after_add_post', 'wpforo_topic_subscribers_mail_sender', 13);

Just note: in this case, the users will not receive an email for replies even if they've subscribed to this topic. 

Users will get an email in case of registration, mentioning, etc. They'll just not receive the emails for the new replies."

Also there are other people who also have a fast website like mine but their forum is slow such as @danniee.

In case of @danniee the issue is different. You can find the solution for the user here: https://wpforo.com/community/how-to-and-troubleshooting-2/wpforo-pages-slow-to-load/paged/3/#post-123533

In your case, the issue is related to the email server. Due to a high subscription count, sending emails takes longer and slows down the process. You should install an email queue to resolve this, and you shouldn't face any issues anymore.