I think that some people are 'doers' and others more passive. It can be annoying to be the one who always organises things and makes the effort, but I don't think it's personal, and I'd be very surprised if jealousy is very often the reason why some hold back - it's just that they are made that way.
When I left F/T work I carried on working P/T to ease me into retirement, but Covid struck, and my P/T work turned out to be 99% home based even after lockdown. I no longer had my old colleagues around, and the friends I had at home were locked down too. I decided that when we could all get out again I would build up my social circle, and I have done that.
I joined a few social groups and went along to things whether I really fancied them or not. I set up a couple of groups of my own, as waiting for others to do the heavy lifting is not my style. They took time to establish, but are now doing well. If there is nothing you fancy in your area, you could set something up - a book club or walking group are good places to start, as you don't need to pay for a venue (you can meet in a library or pub), and there are no start-up costs, but you could look at more specialist groups if they don't appeal.
There are groups (usually FB based) specially for women who want to meet others. Someone suggests going to X place at Y date and books a table, and you put your name down and go*. I have made good friends as well as acquaintances that way, and have organised meet-ups for others. It doesn't happen overnight, but I now have a wide group of people who I could suggest meeting for coffee or a night out, and have even been on holiday with a small group of women I met through a social group.
Again, if there is no such group in your area you could start one. It just takes a post on the local FB page saying that you'd like to start up a coffee meeting at a local venue if anyone is interested. The chances are you will get a lot of replies, and if not you can post again to say that you will be at the venue at a given time if anyone wants to just turn up. You can take it from there when you see who goes and what their interests are. Theatre/cinema visits are a good start, as are Sunday lunches. A lot of people who are divorced or widowed miss having people to do those things with, and others may have partners who work away or are less sociable than they are.
It might feel a bit contrived at first, but you can make connections surprisingly quickly, and it's often the case that others are as nervous as you about making contact.
*If you say you are going to attend something, do turn up, as too often organisers are let down by people backing out at the last minute, and that is not the way to make friends.