Your interpretation makes the verse into a truism hardly worth uttering, much less interpreting.
The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that any should perish, but that all should come to repentance. -2 Peter 3:9
The verse councils patience, reminding believers that just as the Lord’s orchestration of history resulted in the salvation of those in the eternal church thus far, so also are there elect in the future to whom the Lord will reveal his mercy. Believers are reminded that the Lord orchestrated all of history to result in their salvation (O the depth of the riches…). But they are also reminded at the same time to stop being so self-centered in their thinking, that history does not revolve around any one particular believer. History revolves around and is orchestrated by the triune God. The world will end, as the preceding and following verses certainly declare, but stop being so impatient and behold the unfolding of the glorious work of the Lord (especially the future salvation of fellow sinners) and stop pining for the end.
And despite your valiant efforts, still a truism. When you interpret "all" as "all those who repent," your verse ends up saying "all those who repent should come to repentance." That doesn't pass the smile test.