Well, every person's situation is different. You have had a chance to use your Cosmo for awhile before it died so at least you are familiar enough with how well it works for you, which will help you decide if you want another.
For me, I got my Cosmo for two big reasons:
1) awesome physical keyboard.
Like you I don't like on-screen keyboards. Trying to do command line stuff with on-screen kbd is quite a PITA even with the Hacker kbd. With onscreen keyboard I don't look forward to replying to emails, and I'm terse with SMS / WhatsApp messages.
Since shortly after I backed my Cosmo, though, I have started using a Thinkpad bluetooth keyboard with TrackPoint and with 3 BT device memory, so I can quickly switch between my work PC, personal PC and phone, all from the same keyboard. If you're a fan of TrackPoint like me, this thing is fantastic. If you hate TrackPoint, disregard.
Unless I'm sitting at a desk, I end up using my Cosmo in two-hand thumb-typing mode anyways, which is barely better than on-screen.
So, for me, I would be happy to have a normal all-screen phone and use my Thinkpad BT kbd when I'm at my desk. Out and about, on-screen kbd might be a good trade-off for not having to open-close the clamshell all the time and not having to deal with apps that aren't so good in landscape mode.
[Aside, I've also noticed that even if I force-rotate, it's not just a matter of redrawing the screen. Most of the time it reloads the app, so I end up losing my place on a long webpage, or stuff I was typing disappears, or I have to re-enter my username and password for bank apps ... annoying.]
2) Linux.
The other reason I backed Cosmo was to be able to walk around with a reasonably powerful linux device, and not have to bring a laptop, un-suspend it and setup networking.
I'm still not there yet with my Cosmo, because I don't want to wipe my Android install and I haven't found the time to sit down and do it. My Cosmo is my daily driver, so when I do this I want to take time to get it set up the way I want. I also don't want to have to decide how to allocate my precious in-device memory, 60G Android / 60G Linux or whatever. 128GB might be a fair bit, but it's not enough to feel OK about wasting space in one mode that cannot be used easily in another mode.
There is also the dual-boot annoyance. I want Linux, but telephony and messaging aren't good (yet? ever?) in linux. Meanwhile, there's a lot that Android does really well, not least of which is phone, SMS and messaging, and I want to keep using my Android for the things it is really good at. Dual-boot also means that you have to go through shutting down one OS and booting the other, which is annoying if you just want to to something for a few minutes in the other. While in linux you're not available for phone calls, SMS, etc. Even if those things actually worked in linux, your records aren't synced. A SMS conversation in linux won't show up in your Android history.
If only there were a way to have both things simultaneously. But wait, there IS! Here in this forum, folks have figured out how to do the Devuan thing, running linux efficiently within Android, both available simultaneously. Do your calls and SMS and WhatsApp from Android apps, but do your browsing and coding and IRC and whatever else you love with Linux. You don't have to repartition, and all your Linux stuff goes on the SD Card, so space is suddenly not a problem. So many advantages. Consider that you can use tmux's API for things like SMS and calls, etc. as a bridge to linux. Tasker may help too.
Best of all, you can do the Devuan linux on Android thing from any phone you can root, not just a Cosmo. And if you do, then you can pick a phone that doesn't have a potato for a camera. I mean, the actual hardware is 24MP (supposedly) but until (if ever?) they fix the driver, we're stuck with potato-quality pics. You can also find a phone with a less limited HDMI output.
(Mind you I still have not set up Devuan yet ... Cosmo is still my daily driver and I'll want to take time and ensure I do things right when I root Android ... also not sure if Google Work Profile works in rooted Android even with Magisk, and I need Work Profile for ... well, for work )
So, to sum up, for me, if my Cosmo died today, I would probably:
* Look for a phone with really good hardware, including a camera, good HDMI, root-able, etc.
* Use annoying on-screen kbd while out and about, use ThinkPad BT kbd at desk.
. * If I did this I would probably end up buying another TP BT Kbd or two, just to be able to keep one at home, work and in my bag
* Set up Devuan linux in rooted Android.