"very slow and a complete ghost town with no projects using it " ??
How it is then possible that there have been many projects which announced that they were using NEM blockchain?
How the slowness is measured? Compared to what?
Its easy because all these are bullshit projects that only produce hot air. Try to find one project that is using NIS1 Mainnet for their product.
Guess what, there are none. You can also have a look at the block explorer, most blocks are empty and those who have transactions are mostly transfers to and from exchanges and the occasional spam from Pontifier.
Slowness compared to Symbol and many other "modern" blockchains. Why would anyone choose NIS1 for his project when there are other much faster blockchains that also have much more features and are cheaper to use. The static fees alone make NIS1 not really usable for any serious business. NIS1 has to fork with any mayor price change or TX will either be too expensive or way to cheap.