Some general comments.
Solid State Drives are the fastest, NVMe Gen 4 the fastest of M.2 SSDs. A solid state drive is about 5X faster than a mechanical drive, a Gen 4 NVMe SSD is about 10X faster than a regular SSD. This translates to improved performance when any disk transaction occurs. This includes operations like booting the computer, launching applications, and saving and opening files. The downside is that NVMe drives are the most expensive. A 2 TB NVMe might cost $200 when a 10 TB mechanical drive cost about $200. The cost of NVMe drive above 4 TB are very expensive. At some point as your photography catalog grows you will find yourself have a combination of storage, running the OS and applications on a SSD and having your photo catalog on some type of storage likely including mechanical drives. It is also possible to take an existing PC and give it new life by replacing an internal hard drive with a solid state drive, I have done that a number of times.
Having enough memory is important to give the OS room to run as well as room for applications to run. It is possible to run an OS and many applications with less than adequate memory but the OS will then use disk storage as temporary storage moving data in and out of RAM which will really slow down processing. It is important to have enough memory to handle the OS, all applications you may be running concurrently, and room for the content you are editing. You can often get a little more life out of a computer by simply increasing the memory.
Central Processing Units (CPU) and Graphics Processing Units (GPU) handle the processing. When editing images and video the applications utilize the GPU to remove the graphics processing load from the CPU. The more advanced editing you are doing the more you will see the benefit of a GPU. Not every application can utilize a GPU and not all of the operations in something like Lightroom or Photoshop can utilize the GPU. It is good to have enough CPU power and enough GPU power to handle the task. Many consumer laptops and desktop computers have integrated graphics which means the CPU is handling the graphics processing. This is not an issue when using Word or Excel but can have a big impact when using Lightroom or Photoshop. You can also add a reasonably priced GPU to a desktop without one to significantly improve image processing.
When I find that a computer is struggling I like to watch the task manager in Windows while processing. It will show CPU, Memory, Disk, Network, and GPU utilization values. It helps to see where the computer configuration is lacking.