Being great is a personal opinion, you can be great in your own eyes but for others, you might not matter. Being remarkable is an objective term, you become remarkable when people pass on remarks about you. These remarks can be good, bad anything.
Often people wanting to do great things end up in echo chambers and their work is often appreciated/known in few closed circles. But remarkable work becomes the talk of the town. Remarkable work makes people to comment on your work. In the present world, being remarkable means free social media publicity.
Jio meet might not be a great product but it is remarkable as it has opened so many debates on social media platforms giving them free publicity.
You can objectively measure how remarkable you are but same might not be true for being great.