Could be many reasons, just a few to list: water gets trapped between the driveway and the house in a grass area, not enough pitch from the house to the driveway, or gutters discharge into the grass area, and without proper drainage, an excessive amount of water percolates near the foundation and finds its way into the basement.

Posting a few pictures of the outside will be more helpful.

The old driveway was doing water management work even if that wasn't the goal. Impervious surface against the house sheds rainfall toward the street. Grass soaks it in. Pull enough of that surface and the same volume that previously ran off is now infiltrating within a few feet of the foundation wall.

The French drain is worth pricing out. It intercepts surface water before it gets to the footing, which works when the wall itself is still sound and the problem is water reaching it from above. Less invasive and cheaper than excavation by a fair margin.

It won't be enough if the foundation wall has a failed dampproofing layer, cracked parging, or a gap at the footing-wall joint. A French drain controls what happens in the surrounding soil, not what happens at the wall face. When the wall is the problem, exterior waterproofing (excavation to footing depth, membrane, drainage board) is the actual fix.

Does the leak show up during rain, or a day or two after? Rain-concurrent leaks tend to be surface infiltration, which makes the French drain route more viable. Delayed leaks, or leaks after snowmelt with no active rain, point to hydrostatic pressure against a wall that's no longer sealed.

At seven feet below grade with a wall-entry point, I'd want to see the wall condition before recommending either. A contractor-side breakdown of how this scopes out, interior vs. exterior, and what pushes the decision one way: https://home.renovation.reviews/t/basement-waterproofing-in-ontario-interior-vs-exterior-and-what-a-good-quote-actually-covers-2026/47643