Just to add a data point to this thread: I have 2 Ultras and 2 Roku 3s in use with the two Ultras being the most heavily used. My remotes last for months, over 6 months, and my main Ultra has had the same set for 11 months and is still reporting at 33%.
i do not know why I should have such good luck. I just use regular batteries in all my remotes.
On thing that may, or may not, make a difference: I do not hold my remote when watching TV and I do very little "browsing" of any kind. If I wish to watch something I pick up the remote, navigate to what I want to watch, start it playing and then put the remote down.
With the original motion sensing remotes any movement caused the sensor to kick in. Even laying them on a table could cause battery drain when people walked around if the remote were laid on its round side so it could jiggle when the table vibrated. This caused people to develop the habit of laying the remote on its face so it was less likely to move under minimal stimulus.
I "think" Roku fixed that issue with a remote firmware modification a long time ago but many people, including me, never broke the habit of laying the remote on its face so, if that bug is somehow back, maybe that is the difference.
Aside from that I do not use any Roku remote to control my TV or receivers or anything except the Roku. All my Roku remotes use WiFi-direct, except one forlorn little IR remote in my workshop, so I do not think WiFi-direct is the problem.
Maybe it is location related and batteries just last longer at my two homes. This may be particularly true here in Tennessee where I have spent most of the last year or so. This part of rural Tennessee is particularly laid back and maybe the batteries just are under less stress here. Do batteries even suffer from stress?
Two Roku Ultras, three Roku 3s and a Roku 1
"Part of the secret of success in life is to eat what you like and let the food fight it out inside." Mark Twain
Van Roy's Law: An unbreakable toy is useful for breaking other toys.