As of recently (December 2017), Google has steadily been increasing the length of the snippets that are presented to searchers from their former length of 165 characters to a larger 266 character limit. This expansion is basically synonymous with an expansion of billboard size along the side of a highway, for example, because it now allows those who are ranking in the search algorithms to have more real estate for the description of their content. The hope is that this will allow searchers to get an even better assessment before clicking so that they will be happy with the page that they land on. It also means that there is less room on the screen so that those who are able to rank with a new snippet will push others out of the viewable area.
With the previous snippet length, there were only about two lines of text available, and this meant that any overflow had to be denoted with an ellipsis so that searchers would understand that there was more to be found on the other side of the hyperlink. Now, at 266 characters, there will be about 4, or even more, lines of text available, and it has also been seen by some that the updated Google algorithm is happy to extend this even a little more if the concept only needs a few more words to explain. This is so that the ellipsis would not have to be used when an expansion was small. This might also open up the SERPs to those who are able to leverage this nuance by purposefully providing a description that they know will be automatically enlargened based on this feature.
Also, there is certainly going to be a short-term opportunity for those who are able to get to work and improve their snippet description before the others who are ranking for similar keyword results. The data seems to be showing that only about 51% of SERPs have at least one of these newer and larger snippets being displayed in the results, and so those who are able to get there first will likely see some improved action on their pages that could also help with the ranking of other pages on the domain and long-term positioning.
This also means that there is more room to answer a query in the snippet itself, and that will be a beneficial approach because it will mean that the site is likely to get a higher positioning. So, even if there is a sacrifice of some clicks due to those people who get the answer that they need and leave without clicking, it will still probably lead to an increase in traffic over time because of the better ranking in the Google results. It all amounts to the fact that the SEO experts will be working even harder to tailor that 266 character snippet to the best of their ability now that there are at least a few extra lines to work with.
Google has now officially increased this snippet length after having experimented with it some over the past month or so, and this means that there will likely be even more sites utilizing the advance. It is important to get out there as soon as possible, but some may also be comfortable with just leaving their content as it is and letting the algorithm make its own changes to the snippet. The choice is yours.