If I have to compare using the train rather than flying to Paris, personally, using the train tops it as it have more advantages. Obviously, fear of flying comes into consideration but i will not include it in my list.
Accessibility
It's location. Any major city will have it's station at the city centre. In Europe, the continent is very compact. Anyone need not fly to access neighbouring countries. The necessity of a train station at the city centres provided the need of the people for its' accessibility. In London alone, there are 4 major train stations that cater for commuters going to and from London, to nearby airports and King's Cross St. Pancras is where Eurostar can be accessed when going to Western Europe. Considering the length of time a person needs to prepare in going to airports, the minimum time to be at the airport prior to the actual time of flight, using the train requires less time consumed. A train passenger on international travel only need to be checked-in by 30 minutes before departure, compared to an hour for short flights.
Convenience
Have anyone used the Eurostar before? The chair is huge right? Spacious and comfortable? And legroom? These are just the perks with no extra cost. Spaces between the chairs have about a foot in between. Overall, carriages are spaciously arranged in that it only have less passengers so there's no feeling of being cramped in one's chair.
Now, with group travel. A group of 4 can stay together, facing each other with a wide table in between. Opposite the aisle can further accomodate another 2 people. How cool is that? A bit extra of payment is also possible to be together in one compartment. This is more preferable personally as a group of friends or a family travelling together.
Toilets are very much availabe so convenience for the passengers were well thought off. It doesn't have that feeling you get when the plane dips down suddenly or when it's rough outside. Blissfully comfortable I should say.
Less delay
In a few occasions that I have used the train in going to France, there haven't been any delay at all. There is still a possiblity though so I can't truly rule it out. For one reason to another.
No immigration upon reaching the destination
Am sure, most have watched and seen Jason Bourne getting off his train without passing through the immigration? That's exactly how it is. Passports or ID's are only needed on checking in.
No Ear ache
Does anyone suffer this when flying? It can be very painful that turns people off. A friend of mine and her family from Milan used the train once when going to London just to avoid flying, but the length of their travel totally zoned me off. But this is another story and Milan is a bit far for train travel going to England.
Cons
The length of time to travel by train may seemed longer, but consider the time to prepare plus the minimum check-in time, add them together plus the flight is almost the same time, more or less. But consider one's comfort in using the train, CAN FLYING BEAT IT? Yes, when flying first class.
The fare is almost the same, although a cheaper flight is possible when booked long way before the flight. This applies to those airlines that do short-haul, examples are Ryanair, Easyjet, etc.
A taster...
A street scene in Monmarté today October 1st, 2017.
Music and dancing in la Rue Mouffetard.
Want to take the train with me to Paris?? Allonsy!!
All images are mine, taken with my Samsung Galaxy S7.