I don't think they will last that long. TSMC could bring 7nm, 5nm and 3nm to market because Apple just straight out funded these processes with agreements to buy the capacity exclusively for the first year or so. Even Nvidia couldn't access it till now (if I didn't miss it). Companies are interested in 18A as a second supplier, mainly to increase capacity on advanced nodes. This though requires everything to go better than the plan. Intel wasn't a foundry for others, so they don't have the experience to support different companies needs (from design flow to IP availability like standard cells, ESD, Serdes etc). TSMC doesn't only develop a process but develop all the stuff around it to serve a diverse set of customers. Now, if Intel gets 18A right it's great. It doesn't mean everyone jump on it and book huge amounts of capacity. If the design fliw isn't streamlined and it takes too long to tape-out adoption will not be there. Global Founderies 14nm and 12nm are great examples of this.