A kyced team can give a certain level of trust even though it is not a guarantee to success which is not the sole aim of doing the kyc in the first place, it shows the team are ready and willing to do their best to gain investors trust and be at ease, if investors can be subjected to kyc, I don't see why teams shouldn't.
KYC for the project team is actually only to make them want to be responsible and not immediately let go when the project has failed or when the project does not reach the sales limit they want, so in general it should actually be mandatory for those who want to be part of the team projects.