Yes but the dips give them far more than they used to.
I disagree. I mean, it's not like Hexblade wasn't a thing in 5.0, so that part is already unchanged, and the bonus action punch from Monk really isn't that good if you aren't, y'know, gaining more Monk levels. You have inflated the value of these things in my opinion.
A Martial is a weak build in 5E and remains that way,
For reasons that have nothing to do with the things you're complaining about.
but the dips did not offer as much as they do now because significant subclass abilities were not available at 1st level.
Except most "significant subclass abilities" have been shifted to 3rd level? I have no idea what your complaint even is here.
Weapon Masteries, nick, Pact of the Blade and the new Martial Arts rules make 1st level far more significant for a Martial dip now.
Only "martial"-type characters
get weapon masteries. The new Martial Arts is a d6 bonus action. You could already get that by having a hand axe, scimitar, or short sword in your off hand. This die will
almost certainly be tied to Monk level rather than character level, so you're not going to be making a 1d12 bonus action attack with a 1-level Monk dip. Something you can replace with literally a different equipment choice is not, and never was, a meaningful change.
The only people who can make use of Nick are Barbarians, Fighters, Paladins, Rangers, and Rogues. In other words...that's a power up specifically to martial characters. It's not something you even need to dip for.
Pact of the Blade is effectively unchanged (for the things you have mentioned, anyway)