Apparently they load an insane amount of company data into your browser and expect your browser to do the bulk of the processing. This can be demonstrated by viewing how much RAM each tab of theirs eats up.
I recently upgraded my system to 64GB RAM which helped for a few days - but apparently browsers aren't built to do so much heavy lifting.
Intuit does this to save money on their end.
They don't use ajax (asynchronous background server requests) as that would be server intensive so instead your browser needs to compute any particular transaction in the context of all previous transactions, that's why newer accounts with less transactions run faster.
Their system design is flawed on a very high level. I made a terrible mistake using the online version.
It feels like they rushed to create an online version without investing the time & money to design the system correctly. What's frustrating is the fact that you only realize the issue once you are fully integrated in their system with hundreds of transactions.
