No need at all,
From 1965 to 1985 Englands overall test record against all comers out of a total of 56 series was Won 27, Lost 17, Drawn 12. Hardly the sign of a team in terminal decline.
I will say it once again in case I didn't make myself clear earlier, the West Indies team of that era was a phenomenal team in every single department, no team before or since has had a battery of 6 or 7 world class fast bowlers on call at the same time. Put that together with brilliant openers and untouchable middle order batsmen and you are going to get steam rollered most of the time.
Every other nation struggled against them not just England.
England had a couple of bad series against the Windies, this current West Indies side cannot beat anybody, that is why they are near the bottom of the test rankings.
They haven't won a test series since 2014, have lost the last eight and their only wins just before that came v Bangladesh and Zimbabwe.
