My take (as a previous employee at Betterment): Wealthfront/Betterment/et al came out to much fanfare and the promise of disrupting the traditional wealth management industry.

At first, it seemed like they were right. AUM growth was looking like a hockey stick...this caused some panic at the big firms' who hurried to launch their own offerings (this is like 2015-ish) which were minimal at best, and still mostly just "marketing products" - a thin roboadvisor veneer designed to drive users into their traditional businesses.

Over the next 2-5 years and up to now, it is becoming/has become obvious that roboadvisors are not, in fact, going to disrupt the industry and it's rather a race to the bottom in pricing with razor thin (or non-existent) margins...so the actual robos have largely stagnated and the big firms stopped investing into their own solutions.