The instinct when a device gets frustrating is to replace it, but most everyday complaints — slowness, short battery life, noisy fans — have cheap fixes. A laptop with a mechanical hard drive replaced by a solid-state one feels new for a fraction of the cost.
The questions worth asking are whether the fault is one component or several, whether the manufacturer still issues security updates, and whether the repair costs more than a third of a replacement. Two of those pointing the same way usually settles it.
Security support is the underrated one. Hardware often outlives updates, and a device that no longer receives security patches becomes a genuine risk regardless of how well it runs.
If you do replace, migrate deliberately: back up first, verify the backup, and keep the old device intact for a fortnight until you are certain nothing was left behind.