I am not sure I would say saturated, but yeah, the Sr. SWE market is definitely not as tight as it was a year ago for most role types. However, it does depend on qualifications and company type. Seniors for R&D positions (so, PhD with 5+ years in product-focused R&D) are still basically impossible to hire. Friends tell me that hiring seniors at mid-pay or low-pay companies is still pretty hard.
The more important dichotomy is between mid-career/late-career and junior. The entry level positions are absolutely saturated. CS programs are definitely over-producing at this point.