Unfortunately, not all groups have the leadership they need or deserve and Illumina does not recognize the problems it has. The entire manufacturing operations segment at Illumina suffers from postulating leaders, political hires, lack of onboarding, nonexistent recognition, and in the worst places: a psychologically unsafe environment (think people going around others until they get the answer they want, belittling people's work in front of them by their own managers, derailing meetings to avoid progress in projects management wants to cut anyway because they are too expensive, and a misproportionate focus on cost savings/avoidance over process quality). This includes equipment and process engineers, quality, validation. There is hardly any room for technical work that could allow for real innovation to come down the line because managers are pushing to save every bit of raw material from scrap. Manufacturing operations is often reduced to sitting in meetings with the same people going through endless loops of documentation, writing about technical work that could/should be done but resources are unavailable.
Promotions are based on your perception with your manager and their managers, rarely on merit. On that note also, managers typically hire people based on unilateral decisions and bypass the entire interview committee. 50/50 chance it's someone qualified and ready to do the job.
Take it to HR, and you get one of two answers: 1) what would you like me to do about it? or 2) this is terrible, but you can always leave. Escalate that further up in HR, and they talk down to you to explain that their job is to protect the company and not the employee.
The company rewards and protects incompetent leaders that are good at talking to VPs, and acts like everybody below them is so lucky to work at one of the "best places to work".
There are seriously some talented, smart people with the right values to make not only the product and business work, but the company as a whole. Unfortunately, 80% of the ones I know are looking to leave because Illumina has been on the downhill for some time, and stock is now finally starting to be impacted as well.