GOOD NEWS Did you know that you can install the latest Linux kernel(s) on your older Debian or Ubuntu system?

[Halea]

XanMod provides precompiled Linux Kernels that can be used on Debian or Ubuntu systems, even quite old ones like Ubuntu 14.04.
Most recently I had to install Linux 5.14.x on an old PBX running originally Ubuntu 14.04 with kernel 3.13. You can imagine the stretch!
The installation procedure is as follows:

Install via Terminal​

1. Add the repository:
echo 'deb http://deb.xanmod.org releases main' | sudo tee /etc/apt/sources.list.d/xanmod-kernel.list
2. GPG key:
wget -qO - https://dl.xanmod.org/gpg.key | sudo apt-key --keyring /etc/apt/trusted.gpg.d/xanmod-kernel.gpg add -
3. Then update and install:
sudo apt update && sudo apt install linux-xanmod
4. Reboot.
Meta packages available: linux-xanmod [5.13], linux-xanmod-edge [5.14], linux-xanmod-lts [5.10], linux-xanmod-cacule [5.14-cacule] and linux-xanmod-rt [5.10-rt].

For more info check out XanMod and its SourceForge page.