Eth will indeed become a big spam block chain.
All the languages it supporters makes it very hard to maintain.
Lisk choice focuses on one can give better support.

But JavaScript as language is dangerous for more than simple scripts.
It isn't a full programming language just a script.
It gives huge issues that need to be worked around.
And has limits.
This will likely create large attack vectors if not full dealt with and code highly reviewed  by a big community skilled people.

Surpassing ETH I don't believe.
Look at eth community it is huge.
Same as the amount of devs.

Because of this eth will always be ahead.
Their software is more evolved and have the community to evolve quicker.
Look at the perspective like this if :2 cars race and one is halfway to the finish(eth) and drives with + x15 speed compared to the first that is just at the start.

And next month rootstock start it's test net for developers.
They improved eth network capabilities and limits on a huge way.
As it's a side chain aside bitcoin it uses btc network effect.removes problems by eth mainchain.
And are backed by huge supporter of bitcoin community business,developers,miners,.... .