while searching for some topic we found many post related to "Banned/Block" user who are no longer part of this forum, and deleting the banned user data/record will save a lot of space and also reduce the record per search term. This will also there will be fewer record in the Database and the query will be expected fast.
Note÷ you can create a backup of files in case ones may need it in the future.
OP you don't need to worry yourself because every information or data on this forum contribute nothing for you to experience a congestion or network glitch while making a search through the forum, if you're used to ow the page loads, you will discover that it does not require alot of data connectivity before loading, unlike other platforms that were heavy enough to easily load as this forum is, maybe you can check your own devise storage, delete some junks and free some space if you experience slow while loading.
But i can tell you that those things mentioned by you aren't the cause and every user or post here were archived even though you deleted some from your end, if also does not affect you from enjoying the forum, you can easily search or navigate through boards and threads of your choice.