I recently put some fiber (AOC, to be precise) in a multilevel European building - brick and concrete. It was not trivial, but not a PITA.
25Gbps is for multiple transfers from multiple sites to multiple computers. For example I transfer large files for work (up to 100 GB) from multiple sources and it takes a long time and consumes all the bandwidth in the building. If I download at lower priority (implement some QoS) then it takes even longer. I can see 25 Gbps eliminate the bottleneck and allow everyone in the building to have their regular use (video conferences, movie streaming, gaming, whatever) without me impacting. I would never use more than 1% of that bandwidth on average, but I would peak more than 1 Gbps quite often. Yes, 10 Gbps would be more than enough, but if the cost is the same then 25 Gbps seems more future-proof, at a cost (SFP28 equipment is much more expensive than SFP+).
25Gbps is for multiple transfers from multiple sites to multiple computers. For example I transfer large files for work (up to 100 GB) from multiple sources and it takes a long time and consumes all the bandwidth in the building. If I download at lower priority (implement some QoS) then it takes even longer. I can see 25 Gbps eliminate the bottleneck and allow everyone in the building to have their regular use (video conferences, movie streaming, gaming, whatever) without me impacting. I would never use more than 1% of that bandwidth on average, but I would peak more than 1 Gbps quite often. Yes, 10 Gbps would be more than enough, but if the cost is the same then 25 Gbps seems more future-proof, at a cost (SFP28 equipment is much more expensive than SFP+).