This focuses on desktop / mobile software upgrades, but the same is true of SaaS apps.
More often than not automatic updates are not done with the interest of the user in mind. They are abused to the point where many users - me included - would rather forego all updates (let alone automatic ones) simply because we apparently can not trust the party on the other side of this transaction to have our, the users , interests at heart.
It also - unfortunately - isn’t rare at all to find the user interface of the program that you are familiar with drastically messed up after an automatic upgrade. Familiar menu items may have been moved around, renamed or have been removed entirely. New functionality that you weren’t looking for may have been added, prominently so, taking up valuable screen space. Bundled software may have been installed without your knowledge or consent.
There is a software update “manifesto” of sorts, asking for these updates to be user centric, that is worth reading.
SaaS apps and browsers are mostly “evergreen” – automatic updates that must be installed, rather than discrete versioned releases. Which can lead to the same problem of a user interface that the user no longer agrees with. This is also because all of the data and software is centrally run.