Not without substantial improvement in WIFI technology especially as it relates to interference and bandwidth available. WIFI Hotspot 2.0 technology does make it easier to move from one hotspot to another without signing in to each hotspot, but even in dense urban areas where there are hundreds to thousands of WIFI hotspots, they aren't all publicly available and they aren't all using Hotspot 2.0 technology. Even using a cable tv provider network of hotspots like Charter or Comcast have been developing, the end user would find service spotty and inconsistant. Not that bad if you don't want to move or go anywhere while using your phone but unacceptable for most wireless users.
There are pending technologies that will use WIFI frequencies in the unlicensed spectrum bands to augment licensed frequencies. (See LTE-U
or LAA for more details) These types of technologies/standards may assist the wireless service providers to reduce the number of cell towers that they need to build but it won't have a material impact on the number of existing cell towers. There may be occasions where specific towers are no longer needed - especially those in urban or suburban areas with high ground rent. If you are worried about the longevity of a cell tower lease, please reach out to us.