Depends where you are. The H16 was the youth boat for a while in Europe (with a spi) but this is no longer the case. there is no adult H16 regata that I know of. I can't recall the last time I saw a H16 sailing in a regatta. Most H16 sailors are, at this point, recreational sailors.

The H16 is a fun but completely obsolete boat, even more so without a spi. Heck, the BHCCA (British Hobie Cat Class Association) is the RYA group training the top young cat teams in the UK. The youngest are training on Hobie Dragoon, the older are on not on hobies at all: they sail Spitfires. They do participate in the European H16 championships, but this is not their boat of choice. Their main goal is to get beefy enough to get on a F18.

Same in France, where the youth boat is the SL16, and no young racer will even consider buying a H16.

The US is a special case, with the huge fleets of obsolete H16 without spi. If you get your head out of your country you will see that the goal of the Viper is to provide an alternative to the F18 for the lighter crews who can't switch to the F18 and be competitive there. The H16 is never ever in the picture.