Oh for sure, when I say "soon" it's only relative to AGI.
What I meant to convey, is that theorem proving at least is a well-defined problem, and computers have had some successes in similar-ish search problems before.
Also I don't think pure brute-force was ever used to solve any kind of interesting problem.
Chess engines make use of alpha-beta pruning plus some empirical heuristics people came up with over the years. Go engines use Monte-Carlo Tree Search with straight deep learning models node evaluation. Theorem proving, when it is solved, will certainly use some kind of neural network.