It's not the lack of nutrients that would be an issue - in container gardening, all the nutes must be supplied by the gardener - but rather the deterioration of the potting soil. Unless one is very careful about the potting mix ingredients (hard to do with 99% of any packaged soils), the mix will compress and collapse and impede good drainage and proper aeration. And since that is what impacts how successful any containerized plant will grow and perform, that is why it is suggested to replace the soil at the start of each season :-)

At the very least, I would recommend you dump the soil out of the container and refresh with at least 50% fresh soil mix. And feel free to mix a controlled release fertilizer (CRF) into the soil or water with a liquid fertilizer routinely through the growing season. But you would need to do that with 100% new potting soil anyway....unless you purchased the fertilizer enhanced type, which I do not recommend.

I reuse potting soil, except for the tomatoes, for the reason stated above.

I also agree with what gardengal said. I grow all my tomatoes in huge pots and have some success.... given I'm in CA's Central Valley.

I've reused the same container soil for 2 years in a row for tomatoes. I just added more perlite to keep the soil from being too compacted and added plenty of compost throughout the season. I didn't have any problems except for accidentally overwatering them but that due was to poor timing and just bad luck with the weather.