How would we measure this?

Would we weight the verbs by their frequency? In which corpus? Would we count very rarely used tenses? What if the irregular falls into a pattern shared with other verbs? What if it's predictable by phonetics and not an actual stem change? What if one language reflects it in pronunciation but not in orthography? What if it varies by dialect?

I hold: we could invent some statistic to support either conclusion. People graduate and publish with far more subjective scholarship.

Is ir a representative sample?

It's hard to theorise about a language-wide shift based on the example of one verb that is moderately to highly irregular in almost every language for which I know the conjugations - English, Russian, Armenian, Spanish, Italian, French, Serbo-Croatian, Greek, German, Yiddish, Alemannic - despite a tendency to regularise verbs... - and even - consulting Wiktionary... - Hungarian. Especially in Romance and SAE.

Across languages, to go is usually as irregular as any verb after to be, along with to come and modal verbs. In fact, Which languages have a conjugation of to go that is totally regular? is a good question. (The best candidates that come to my mind are maybe Macedonian иде and Turkish gitmek and literary Persian رفتن. But all with caveats.)

There are forces that lead to regularisation of verbs, just like their are forces that lead to irregular verbs, including suppleted verbs, and generally to verbal morphology in the first place. Regularity at the lexical level is a function of frequency, regularity at the language level is a function of typology. So it's really a language change cycle question.

I'll compensate for my ignorance of Latin by claiming we cannot answer this with something like "42% more irregular".

How would we measure this?

Would we weight the verbs by their frequency? In which corpus? Would we count very rarely used tenses? What if the irregular falls into a pattern shared with other verbs? What if it's predictable by phonetics and not an actual stem change? What if one language reflects it in pronunciation but not in orthography? What if it varies by dialect?

I hold: we could invent some statistic to support either conclusion. People graduate and publish with far more subjective scholarship.

Is ir a representative sample?

It's hard to theorise about a language-wide shift based on the example of one verb that is moderately to highly irregular in almost every language for which I know the conjugations - English, Russian, Armenian, Spanish, Italian, French, Serbo-Croatian, Greek, German, Yiddish, Alemannic - despite a tendency to regularise verbs... - and even - consulting Wiktionary... - Hungarian. Especially in Romance and SAE.

Across languages, to go is usually as irregular as any verb after to be, along with to come and modal verbs. In fact, Which languages have a conjugation of to go that is totally regular? is a good question. (The best candidates that come to my mind are maybe Macedonian иде and Turkish gitmek and literary Persian رفتن. But all with caveats.)

There are forces that lead to regularisation of verbs, just like their are forces that lead to irregular verbs, including suppleted verbs, and generally to verbal morphology in the first place. Regularity at the lexical level is a function of frequency, regularity at the language level is a function of typology. So it's really a language change cycle question.