The 3GPP standard leaves a lot of implementation freedom in many areas and there is a huge number of patents on everything. So in practice licensing is a big issue and keeps new entrants at bay.
Nokia thinks it is in good shape because without Huawei there is indeed not many threats. Starting from scratch is hugely costly and takes many years. In any case Nokia has no choice but to be "committed" to Open RAN since that's what telcos want.
IMHO, Open RAN is a push by telcos to commoditize the infrastructure and to avoid being locked in because key interfaces are proprietary.
In the UK where Huawei is on a phase-out, Open RAN is a bet by operators to ensure that they have more than 2 vendor options. They are required right now to use 2 vendors, so they are not solely reliant on any one company for their equipment.
Most operators used 2 radio vendors, in order to keep things competitive when buying more. All have exposure to Huawei to
some extent in their networks.
If there are only 2 permitted credible radio vendors, then pricing on the "new" second vendor is hardly going to be competitive - where else will you go? You can't go with one vendor, and if you did, their pricing would be ramping up as well, as they know you only have one other choice.
Open RAN presents an interesting insurance policy for operators, and Vodafone UK has even announced it will build a couple of thousand sites using less prominent vendors' equipment. This will get them better pricing going forwards from their existing vendors (as there's an onboarded alternative supplier), as well as give them a new option they might wind up preferring.
Right now though, with the proprietary nature of X2 (in the real world - the standards suggest it's not proprietary, but it absolutely is proprietary), you can't deploy interoperable radios, and that keeps your vendor choice limited. If operators can run a procurement and buy a box from one of five companies, that feels a lot better for their shareholders.
Nokia thinks it is in good shape because without Huawei there is indeed not many threats. Starting from scratch is hugely costly and takes many years. In any case Nokia has no choice but to be "committed" to Open RAN since that's what telcos want.
IMHO, Open RAN is a push by telcos to commoditize the infrastructure and to avoid being locked in because key interfaces are proprietary.