1st link - "Premier League remains for over a decade the league with the firmly lowest point difference" i.e the most competitive.
2nd link - "the Premier League has been the most competitive major European soccer league during the past decade "
3rd link - no quotes but the figures show that the PL from 2011-2016 has been the second most competitive after Ligue 1.
Interesting links. Thanks, but have you actually fully read and understood these studies?
The first link evaluates the seasons 2000-2017.
Fig 1 shows the point difference between 1st and 2nd, with PD being closer then PL
Fig 2 shows the point difference between 1st and 5th , with PL being closer then PD
Fig 3 shows the point difference between 17th and 20th , with PD being closer then PL
The second link evaluates the seasons 2009-2018
Fig 1 and 2 show the average number of game left until the title is decided, with PD being marginally closer then PL. This Similar to Fig 1 from the 1st link
Fig 3 - 7 show the point difference between 1st and 2nd, with PD being closer then PL. As in study 1
Fig 3 - 8 show the point difference between 1st and 5th, with PL being closer then PD. As in study 1
Fig 9 shows the number of different champions within the last 5 and 10 years with PL having more then PD
Fig 10 shows the number of different tems in top 4 with PL having more within last 5 years and PD within last 10 years
Fig 11 shows betting odds for promoted teams winning against the standing champion with PL being closer the PD
Fig 12-17 shows points dropped of champions vs 5 bottom sides, with with PD being marginally closer then PL
Fig 12-18 shows points dropped of top 3 vs 5 bottom sides, with with PL being closer then PD
The third link evaluates the seasons 1997-2016 and uses a metric where the point difference between first and last within a cohort is normalized to the maximum possible point difference
Fig 1 shows that comparing the whole league PD is clsoer then PL
Fig 2 and 3 give examples
Fig 4 shows the temporal evolution grouped into 3-4 year periods and that between 2011/12 and 2015/16 PL was closer then PD
Fig 5-9 give again the temporal evolution for 4 subgroups of 5 teams each. For the last period 2011/12 and 2015/16 the PL was closer in the first subgroup (Top) 5 the PD and the PD was closer in the subgroups 2,3 and 4
How can you post these links and state "It's not really a matter of opinion when it can be largely quantified." To me this looks more like, you took your preferred stat or quote and ignored everything else.