In 2013, a former Android engineer said that sticking the "check for update" button on the smartphone was a waste of time. Four years later, things change for the better - as long as you have the latest Google Play Services.
Android
Android
Photo: Canaltech

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Now the "check upgrade" button works as it should.
At that time, Google was gradually releasing updates from Android and that meant that in the first 48 hours, only 1% of the devices could do the update. So even if a new update was ready to be downloaded, pressing the update button did not help if that 1% was already filled.
The refresh button worked the first time, but the next few taps were ineffective if the user was away until the next 25% batch started. If the user was not part of this group or had not touched the button in time, he would have to wait until the next batch.

Continuous update

Now the process works differently. Google has modified the refresh button to flag the action as "user-initiated" and ignore the 1% or 25% limitations. In other words, if an update is ready for deployment, even if it is in the early stages, you can keep pressing the button it will continue.
This change should work only on Google products such as Pixel or Nexus.Samsung devices such as the Galaxy, LG or HTC series probably still work differently.