Things that have changed on tumblr since I started using tumblr in like 2009
Tumblr servers used to crash all the time and you got this screen
Around 2012 tumblr rolled out tumblr crushes for a couple years where you could see who you reblogged from the most. It was amazing and I miss it
back in 2010 you could comment on posts, but the only way you could respond was by screenshotting the notification and posting it as an image. Then you were able to post it as ____replied to your post. Now it seems that is dead with the comment function.
No messages at all, then the message box opened but you couldn't respond so you had to take a screenshot and post on your blog or send another message that had no history of the first message to the person you were talking to. Eventually you could respond privately or publically. And then FINALLY they rolled out the chat function. THIS is a definite improvement.
gif limits use to be so low that if you wanted a 500 pixel gif, people would split it into 3 different images to be under the limit. Making gifs is obviously still an art form but my god the magic you used to have to pull to get it to post on tumblr
clicking on a blog used to take you to their actual tumblr page username.tumblr.com and everyone had custom html. Now it is such a hassel to get to anyone's blog.
Dash didn't used to have endless scroll so you had to actively push a button to get to the next page.
Obviously all the buttons have changed and you can post videos etc. I'm sure there are tons more
Things that haven't changed: the tag search function has always been, and will always be, completely shit