In 2011, I started using a Blackberry Bold 9780, until 2014. The usable keyboard made me think that a device like this could replace laptops and desktop computers. Together with a functional browser and the trackpad (which allowed using mobile-unfriendly websites), the Bold was a great device for me.
The Blackberry Classic I used 2015-2017 was the pinnacle of this idea, together with a prescient gesture interface and many great UI innovations which have been since lost.
The Blackberry KeyONE I used 2017-2021 was the last device I used that had this greatness.
Since then, I believe the loss of physical keyboard phones means that some uses of the smartphone have disappeared.
Clicks Communicator
Clicks Power Keyboard
Keyphone
T-Deck
T-Keyboard
Beepy
Cardputer
Mecha Comet
ZitaoTech refurbs keyboards, but they seem to be permanently out of stock.
The Q25 project is a project to put an Android phone inside a Blackberry Classic shell.
The main use of a pocket computer with a physical keyboard would be communication. Unfortunately, many communication platforms I use are closed, so I can only use them with an Android (or similar) device. If this was not the case, using devices with other operating systems would be more feasible.
Although I do not use WhatsApp a lot (I use mostly Telegram), living in Spain it is unavoidable. I hope that the DMA will allow me to send messages to WhatsApp users through something that has an API, the DMA does not seem to be effective as of now.