The article argues that newer versions of constitutions are often overly lengthy due to attempting to include too many laws within the constitution, which can cause problems. The article argues: "Overly long constitutions often create conflicts between articles that can only be resolved with further tampering. And “if everything is highest law, then nothing is highest law anymore,” points out Dr Versteeg. Omnibus amendments require voters to balance the merits and drawbacks of many changes at once, making it harder to generate consensus."

In brief, the article's view is that the inclusion of too many laws in more recently-written constitutions leads to greater incentives for constitutional rewrites as times and political views change, which is why the article favours shorter constitutions that guarantee fundamental rights, and are thus difficult to rewrite.

[1] (Paywalled, though I've included a summary above): https://www.economist.com/international/2022/08/25/dictators...