Data from the Copernicus program has always been fully available, served with a nice web UI, API for both near real time data and archives.
It's the best source of open satellite data by far.
As for the licensing, I never actually looked it up, so maybe you're right.
The licensing commonly restricts you to small hobbyist use cases. There are typically restrictions on use of data, the amount of data, and retention of data. I've never looked at Copernicus data before but it appears to have the same kinds of restrictions. This is the licensing equivalent of "source available" rather than true "open source". Hopefully they are improving on this front.
While the data may be available in theory, no one ever invests in the data infrastructure that would allow people to access it in practice. They always have a nice website and API but it is like trying to watch Youtube over a dial-up modem. Usable access is reserved for researchers with an approved use case.
The US government does an unusually good job at both of these in my experience. Even when US public data sets that are not readily available online, you have to contact someone, it is usually for good reason. For example, because they are multi-exabyte data sets sitting on tape somewhere that almost no one ever asks for.