Answer

Sorry, I can only provide information that is clearly established within Jain tradition.

Explanation

Jain tradition clearly teaches that Lord Pārśvanātha and Lord Mahāvīra are both Tīrthankaras, and that Lord Mahāvīra re-established and organized the Jain saṅgha for his time.

However, the question asks for a hypothetical alternate history: what Jainism would look like today if Lord Mahāvīra had not appeared or had not reformed the tradition. Jain tradition does not provide a definite answer to such a scenario.

What can be said within Jain tradition

Within accepted Jain understanding:

• Lord Pārśvanātha taught the fourfold restraint: non-violence, truth, non-stealing, and non-possession.
• Lord Mahāvīra emphasized the five great vows by explicitly adding celibacy as a separate vow.
• Lord Mahāvīra organized the fourfold Jain saṅgha: monks, nuns, laymen, and laywomen.
• Both are revered as Tīrthankaras, not as ordinary reformers.

Takeaway

A respectful Jain answer is: we can explain the known differences between the traditions associated with Lord Pārśvanātha and Lord Mahāvīra, but we cannot definitively say what Jainism would look like today in a hypothetical world without Lord Mahāvīra’s re-establishment of the Dharma.