I’ve heard people say WordPress and open-source in general is not secure. I believe otherwise. Simply keep the app and its associated plugins updated and you’re good.
If you customized your theme, the next theme update will wipe your customizations so seriously think of creating child themes. It’s easier than you think.
Should the plugins you use stops development then ditch it and look for another plugin.
Sometimes the process is tedious but you’ll feel more secure about your WordPress site.