Many crypto tokens are dividend producing assets, just like most separate corporate bonds have yields.
Sure there may be somebody wishing the dutch east india company's bonds were successful in underpinning global finance for 500 years, but the reality is that it pioneered a high yielding asset class.
In crypto, there are investible assets, and many people want them as they can gain decent yield from them. Those networks don't require mass transactions per block to be valuable. But you can also create applications on those networks to make them even more valuable.
This makes their networks more secure quicker as well as turning nodes into investments in themselves. The amount of that currency you can earn in a year is the yield. This promotes price appreciation on the markets, and for those fearing mass dumps and market corrections it is prudent to realize that node operators all have different time horizons, just like any dividend investor in stocks.
This is all complementary to whatever else you would like to use those networks for.
With yields being around 8% annually, there is plenty of room for other market participants to discover these networks and accept lower yields.
Key words to look for are Supernodes, harvesting, masternodes, staking
When any network with those things become valuable and liquid enough then ICOs can happen with those currencies being the funding mechanism for the next leg up.
Each of these phenomenons have to be evaluated individually, for their interesting and their most dubious aspects. Yes many ICOs are organizations with no more backing than the blue skies of Kansas, but they don't have to be dubios. It helps to see the ecosystem as a whole, and this ecosystem is a new evolution of capital formation.