Alternatively, what if it was Shakespeare not Marlowe who was killed in Deptford in 1593. Would Marlowe have the amount of fame now that Shakespeare does IOTL?
Marlowe, unfortunately, didn't have the same technical skill that Shakespeare displays.
Shakespeare's work actually embodies quite a jump forwards towards modern dramatic conventions. Prior to him, drama looked back a lot more to Medieval theatre- if you read Marlowe's
Tamburlaine, for example, it plays out very much like a series of tableaus without the fluid plot and character development that Shakespeare used- Marlowe's
Dr Faustus comes nearer to Shakespeare but he was still comparatively raw and underdeveloped when he died.
In many ways Shakespeare was the flagbearer of a paradigm shift in English drama and a TL without him would be very different.
At the very least we'd be linguistically poorer- Shakespeare coined or popularised a surprising number of words and phrases.
You can never underestimate Shakespeare- the man was a genius, one of those few unique Great Minds that sometimes enter our world.
Our revels now are ended. These our actors,
As I foretold you, were all spirits and
Are melted into air, into thin air:
And, like the baseless fabric of this vision,
The cloud-capp'd towers, the gorgeous palaces,
The solemn temples, the great globe itself,
Yea, all which it inherit, shall dissolve
And, like this insubstantial pageant faded,
Leave not a rack behind. We are such stuff
As dreams are made on, and our little life
Is rounded with a sleep.