Thinking some more, I wouldn't make a marinara with fresh tomatoes but what you could do is a sun dried tomato pesto but dry the tomatoes yourself. Super easy to do, get some Roma tomatoes, quarter them, a little salt and olive oil then at 200 in your oven for 2-3 hours.

You can then blitz them in a food processor with pine nuts, basil, garlic, olive oil and parmesan cheese and it'll get you the intense tomato flavor I think you're looking for.

You're going to get better results with canned than with fresh. Fresh tomatoes are picked while still green so unless you grow them yourself, the flavor is better on canned ones (which can be picked ripe).

Try adding tomatoes paste to up thr tomato flavor.

I used Cento San Marzano whole tomato can to make the sauce and didn’t like the taste. Does anyone have a good recipe that uses fresh tomatoes?