Jessie is your typical 'Messy Millennial Woman' and comes ready baked with all the tropes you'd expect from that stereotype. Casual jobs she's not really interested in? Tick. Chaotic dating pattern of her own making? Tick. Speaks her thoughts with no filter? Tick. Being impulsive, flaky, spontaneous and self-destructive? Tick, tick, tick. What does Tom see in her?!
And what does she see in him? He's pleasant enough but dull and boring with no discernible personality. His family seem great with bags of wit - why did he not inherit any of those genes? He's a famous film star, is that the attraction? Why would MMW be interested in that? Wouldn't MMW take that Cinderella idea and reject it for the nonsense it is?
And together they are a terrible couple. They lack chemistry which is one thing (though if they had that the show would be much, much better). But here are two adults completely incapable of having a normal conversation. Jessie, forward and brash in nearly all situations, is suddenly incapable of telling Tom she likes him and recognising, despite all the obvious signs, that he likes her. Instead, inexplicably, the baseline expectation is that the other one doesn't really want to be there and just wants an excuse to go home. Maybe that makes sense in the beginning but after they start 'seeing' each other it's still happening and it's just daft - they never seem anything other than strangers speaking different languages.