One thing to consider is that train seats are significantly roomier and more comfortable than airline economy seats. This site[1] lists most high-speed trains

One thing to consider is that train seats are significantly roomier and more comfortable than airline economy seats. This site[1] lists most high-speed trains having seat pitch of >900mm (or 35in), some reaching 1,000mm (39in). According to [2] most airlines have seat pitch of 31-32 in. [1] https://misc.transport.rail.europe.narkive.com/ffTnAi0D/seat-pitch-on-high-speed-trains https://misc.transport.rail.europe.narkive.com/ffTnAi0D/seat... [2] https://www.seatguru.com/charts/longhaul_economy.php https://www.seatguru.com/charts/longhaul_economy.php