After losing an account on LinkedIn with 10 thousand contacts, 12 recommendations, and career history (with messages indicating non-commitment to the user agreement), is a platform like LinkedIn considered enough for a career development plan?
LinkedIn knows the information you have shared, but doesn't know you and cannot have a conversation with you. Also it doesn't care about you. It just cares about your subscription, your network for its algorithms and attending to Ads. It wants to be a jobs network, but most subscribers want it to be a professional exchange. I am an online and AI enthusiast but these platforms do not yet have the sentience and capability to be your career coach. LinkedIn is not able to explore your goals and aspirations, challenge your assumptions and help you consider choices. A trusted manager, critical friend or a coach is your best bet. Someone who can ask you powerful questions, reflect, challenge, and work with you to broaden and test your thinking.
Your question is, "Is LinkedIn enough?" That seems like two different questions.
1. Could I use LinkedIn and nothing else and still develop my career?
2. Do I need to use LinkedIn to develop my career?
As Crispin Garden-Webster wrote, that website does many things, including helping people to find jobs. However, there are plenty of other ways to find jobs. None of my jobs has ever come from LinkedIn. However, a good friend of mine has found most of her jobs on LinkedIn. So, yes, it can work for that goal, but it is by no means necessary.
If you want to develop your career, it helps to have a good professional network. Many websites can help with that. However, websites are not a requirement. Meet others in your field. As Crispin said, finding people whom you can talk to about your career development is what you really need.
You can find those people in real life. We know that in person meetings build stronger bonds that those online. So, find those in your field, especially those above you but really at all levels. Then, talk about each other's lives and careers.
Depending on one website, any website, creates a huge risk, which it seems you have encountered. Being "de-platformed" can be hugely frustrating. One solution is to not depend on any one platform.