Unless you’re doing, like, editing on a NAS, the main reason for 2.5 would be concurrency - maybe you’re watching a video, downloading something from steam, copying shit from the NAS, maybe there’s three of you and we’re talking the link to the switch.
Careful with future-proofing. Gear isn’t eternal, not even ssd, nor can you predict how your needs will change perfectly. I do have SSDs in my server-that-acts-as-a-NAS, but that’s the reason: it’s primarily my “pet” home server, I do “local stuff” via ssh on it. If I ever attach external mass storage to it, you can bet it’s gonna be spinning platters, valuing reliability over performance by a wide margin.
Fun fact, this post comes off way more OCD than any amount of time cataloguing. Like not "OCD enough to be a one-post diagnosis," but still more. Because actually, OCD isn't about keeping things neat. It's quite often the opposite, like for example intentionally alienating a social group ^_^