Well, in my opinion, all people browsing here should not have like 128 Kbps connections any more. A difference of some tens of kilobytes is not that significant unless you want to cram a large number of images on one page, which is rare, at least on this wiki. If that was an issue, then everything should have employed ways to shrink the size down on export/receive already.
Another thing to note is that MediaWiki stores all past revisions of all pages/files. That means when you upload an optimized image, you are taking more storage space in the server rather than saving it. So you should make sure that the size difference between the old image and the new one is reasonable before deciding to upload.
Those are just my few thoughts, if you feel doing this is good then you are perfectly fine to keep doing so.
Well, in my opinion, all people browsing here should not have like 128 Kbps connections any more. A difference of some tens of kilobytes is not that significant unless you want to cram a large number of images on one page, which is rare, at least on this wiki. If that was an issue, then everything should have employed ways to shrink the size down on export/receive already.
Another thing to note is that MediaWiki stores all past revisions of all pages/files. That means when you upload an optimized image, you are taking more storage space in the server rather than saving it. So you should make sure that the size difference between the old image and the new one is reasonable before deciding to upload.
Those are just my few thoughts, if you feel doing this is good then you are perfectly fine to keep doing so.