Well no, not just yet, but there will certainly be fewer of them in the coming years.
The merger between Orange and T-Mobile UK, if it goes ahead, could see up to 8,000 masts decommissioned as the two networks share infrastructure. The 3 network have also agreed a deal with T-Mobile to use their network which could see up to 5,000 masts disappear.
Now O2 and Vodafone are looking to cut costs. With 24,000 masts between them, a deal to share masts means several thousand could go over the course of the next few years.
If this trend continues it could well mean that, in the fullness of time, the mobile phone infrastructure will be shared by all networks. Differences in coverage would no longer be an issue and with all of the major networks sharing the investment, coverage could well improve in more remote areas where it is currently problematic.
A shared network would also help with the rollout of future technologies such as 4G which will become necessary to increase mobile data usage amongst customers who currently are sceptical about coverage and speed on mobile devices.