I do think it's alarming and unique that we've had 8 Mercedes wins in 8 races, 6 Mercedes 1-2s in 8 races, and 39 out of 40 possible top 5 positions going to the same 5 drivers. On paper that's extreme predictability, but for some reason it doesn't feel quite as bad as those statistics. Ferrari had a win well within their reach in Bahrain, Baku and Montreal, and Red Bull had it in Monaco. Also, whilst less important, there's wild race-to-race form swings in the midfield. And there's actual possible, plentiful overtaking. And Hamilton's lead over Bottas in the championship isn't that huge, all it takes is 1 DNF and a couple of bad races (in theory). So IMO it's not as bad as 2002 and 2004 were, which was the all-time lowest point for me.
I also think people have forgotten just how ridiculously bad things were in certain seasons in the past, by looking at it with rose tinted glasses. 1992 and 1993 are seen as part of the golden era of F1, lauded for some historical great moments like Donington 93 or Monaco 92 by Senna, yet those moments were rare and those seasons utter piss in terms of a championship battle, with a car that could finish a race 50 seconds ahead of everything else, and a clear gulf in pace between the #1 and #2 driver in it (in 93 Hill eventually caught up to Prost but by then the championship was all but sealed). However I do understand the point of view that cars and tracks were a lot more "pure" back then, that it didn't matter if the championship fight was boring.
There's also been seasons with a really entertaining championship fight on paper but pretty dismal racing on track - 2010 was a particular low for me there. A really tight 4-way title battle!... But with rock hard tyres, no DRS and no refuelling, this meant no strategy and no passing and usually cars stayed in a immutable pace order from lap 1 to the last lap.
So my opinion is 2019 has been pretty bad, but not the literal historically lowest of all, or all negatives in every single aspect.