That reminds me of the Monty Python sketch where the head waiter commands to sack the entire washing staff because of a dirty fork.
I would say firing 25% would be enough assuming you start from the top down. User hostile software usually hostile by design.
I don't think firing 25% would be enough. Ultimately the entire purpose of the company is to provide a solution that allows companies to pseudo-comply with the GDPR without actually complying.
Actual compliance would require removing all the trackers & other bullshit and then you no longer need a "consent management platform", therefore this company ceases to exist and 100% of the employees are let go.
If you ask people whether they want to be tracked (in a GDPR-compliant way, which involves listing all the data points collected, how is it stored & used and with whom it is shared) 99% of people will outright say no, therefore the best course of action is to remove the trackers and no need for this company to exist at all.
/s