Define 'last for years'.

You can focus on something that last for years in storage and still be usable. Or focus on usable after continuous use for years. Or something in between. There is always a trade off is size, weight, price, ergonomics, etc. Define the use case and pick accordingly.

Ferro rods corrode; a sparklite uses a tiny one and is enclosed, so it's hard to protect the rod itself and the rod is tiny to begin with. You could seal it in a proper package; but that defeats the sparklite main advantage; one hand operation. A big fat basic ferro rod can be easily wiped dry after use, coated if needed and just has more of it. Both have their ideal use. You also get things like the blastmatch which sits in between.

Waterfilters; for long term storage and use at home; i have a ceramic one. Tried and tested technology. It's slow because the filter surface is limited, but you can scrub off the filter surface and basically reset it. Which is, in mine experience, far more effective and reliable than backflushing a hollow fiber filter like the sawyer. For long term use, that is more important. But for portability; I just go for the sawyer and carry extra bags (the ones from sawyer aren't great in quality/not that durable) and tabs as a backup.

The easiest way to see how something is designed is to look at the target audience. For 'camping' it generally means small/light/limited use. For 'industrial' usually means last for years in a continuous use (although a lot of proper professional brands, don't need to advertise it as such. They just use there solid reputation).