It isnt very far fetched to believe that having a psychologist to help the players cope with the immense pressure, critique from fans, org, themselves etc. can have an effect on performance and consistency.
Sports psychologists are literally used in every big sport to some extent and if the players even felt like they could have some benefit from using one, its a bit weird that the org wouldnt get them that help.
In the highest level of play, the differences between teams come to very small details and if all other top teams are using a sports psychologist and you arent - and you struggle with consistency, its a no brainer for me to at least give it a shot.
Also YNk mentioned that they didnt even have an analyst to help him and NiKo with preparation, strategies etc. Thats just mad.
Look at the structure behind the best teams like Vitality and Astralis, they have everything they could need and more. If they just have the right persons to do the job, they will be able to get so much better preparation for each game and evolve their game tactically. There isnt enough hours in a day for one or two persons to do the same job.