I have been in several industries already: insurance (life and property), telecom, telecom DoD, investment banking, pharma. Every single one of them is full of H1bs except for telecom DoD. Though some companies are worse than others, it greatly depends on the company's culture.
For example: telecom IMO is the worst of all. They were were doing the H1B long before everyone else. There were large numbers of H1Bs there prior to Y2K. There are still large numbers of H1bs there. I have a friend that is involved with the layoffs, she does the financial analysis on it. She tells me they are continually laying people off even now. Never mind they have been laying people off continuously since the early 90s. Its a pit of a place to work and they pay shit.
Telecom DoD is a different animal. They are usually set up as wholly owned subsidiaries of the parent company and you need a secret clearance or above to work there. No H1Bs at all but there are quite a bit of foreigners who got go the Federal minority owned business gravy train. Lots and lots of so-called Indian-American owned body shops who place bodies there though the bodies all have to be citizens and have to be able to get security clearance.
Insurance is full of them but the environment is at least calm.
Investment banking is full of them but the environment is very stressful.
Pharma is also full of them except in research. All their routine operational stuff is in India and there are tons of Indian body shops that come in via another vendor. But the environment is at least calm.
BTW outside of DoD, pharma pays better than all of them.