This was me last year, and actually still is. I remember JorisBohnson2 - really pleased to hear about your promotions and that you now have a role that you wanted.
I'm afraid that I don't have any advice Mondui other than what others have said about not taking things personally and keep going. I also got lots of interviews but always received the reply (when they bothered to reply, that is...) that 'someone else had more relevant skills and experience' which I realised didn't really mean anything. They know what skills and experience candidates have from their application.
The last interview I had was at the end of August, when I received the feedback that I'd given the best interview, that my presentation had blown everyone else's out of the water, that the person who phoned me really wanted to work with me, but they'd decided to give the role to a candidate who knew some of the stakeholders.
Obviously if 'knowing stakeholders' had been on the application form I wouldn't have even bothered submitting an application.
On the plus side, and do keep hold of this, other people on the threads at the time did get job offers, some after lots of rejections.
Fortunately, some freelance work came in so that I could take a break because spending days completing application forms and preparing for interviews which were absolutely fruitless was completely wrecking my mental health. My mum also died (very old and very ill, so not unexpected) and I'm the only relative in the UK so am sorting out her house etc.
But now a New Year and nearly empty diary and I need to start again. Just writing this is bringing back all the despair and hopelessness. I'm in the same position as I was when I started looking (October 2020!) except older and with even more years of being self-employed neither of which are attractive to employers from my experience.