Do not generalize it with age, Mia Jerkov is also 31 years old however look how enthusiastic and effective she plays. Also Glinka did her best and contribute a lot to Vakıf's success. Montano is 30 yo yet still amazing etc. So the point is not related to age but about enthusiasm of player.
One or maximum 2 players with ages over 30 can be tolerated and sometimes, this is even better if a team has one player of age over 30. Mia of Bursa is the only one with age over 30 and this is good for young Bursa team who needs her experience of Mia, not much different than Glinka's mission in last years of Vakif. Youngsters may need experience of Mia, but, not Ana Tiemi who is at 25 and we see this in results, in success of Bursa after transfer of Ana Tiemi. Games are usually won by players of ages between 23-28 as this age range is prime age in women volley. The others, youngers or olders, contribute.